diff --git a/pom.xml b/pom.xml
index 09ce2f3d..04cb2a0a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -38,6 +38,12 @@
             <artifactId>spring-core</artifactId>
             <version>5.1.5.RELEASE</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/main/java/com/epam/izh/rd/online/entity/Author.java b/src/main/java/com/epam/izh/rd/online/entity/Author.java
index 166be587..ff95012c 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/Author.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/Author.java
@@ -20,4 +20,76 @@
  */
 public class Author {
 
+    private String name;
+    private String lastName;
+    private LocalDate birthdate;
+    private String country;
+
+    public Author() {
+    }
+
+    public Author(String name, String lastName, LocalDate birthDate, String country) {
+        this.name = name;
+        this.lastName = lastName;
+        this.birthdate = birthDate;
+        this.country = country;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public LocalDate getBirthdate() {
+        return birthdate;
+    }
+
+    public void setBirthdate(LocalDate birthdate) {
+        this.birthdate = birthdate;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(String country) {
+        this.country = country;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Author author = (Author) o;
+        return Objects.equals(name, author.name) &&
+                Objects.equals(lastName, author.lastName) &&
+                Objects.equals(birthdate, author.birthdate) &&
+                Objects.equals(country, author.country);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, lastName, birthdate, country);
+    }
+
+    @Override
+    public String toString() {
+        return "Author{" +
+                "name='" + name + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", birthdate=" + birthdate +
+                ", country='" + country + '\'' +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/entity/Book.java b/src/main/java/com/epam/izh/rd/online/entity/Book.java
index 08bdccb8..8f079869 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/Book.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/Book.java
@@ -17,4 +17,52 @@
  */
 public abstract class Book {
 
+    private int numberOfPages;
+    private String name;
+
+    public Book() {
+    }
+
+    public Book(int numberOfPages, String name) {
+        this.numberOfPages = numberOfPages;
+        this.name = name;
+    }
+
+    public int getNumberOfPages() {
+        return numberOfPages;
+    }
+
+    public void setNumberOfPages(int numberOfPages) {
+        this.numberOfPages = numberOfPages;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Book book = (Book) o;
+        return numberOfPages == book.numberOfPages &&
+                Objects.equals(name, book.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(numberOfPages, name);
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "numberOfPages=" + numberOfPages +
+                ", name='" + name + '\'' +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java b/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
index a9834db4..fb67fb6e 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
@@ -21,4 +21,66 @@
  */
 public class SchoolBook extends Book {
 
+    private String authorName;
+    private String authorLastName;
+    private LocalDate publishDate;
+
+    public SchoolBook() {
+    }
+
+    public SchoolBook(int numberOfPages, String name, String authorName, String authorLastName, LocalDate publishDate) {
+        super(numberOfPages, name);
+        this.authorName = authorName;
+        this.authorLastName = authorLastName;
+        this.publishDate = publishDate;
+    }
+
+    public String getAuthorName() {
+        return authorName;
+    }
+
+    public void setAuthorName(String authorName) {
+        this.authorName = authorName;
+    }
+
+    public String getAuthorLastName() {
+        return authorLastName;
+    }
+
+    public void setAuthorLastName(String authorLastName) {
+        this.authorLastName = authorLastName;
+    }
+
+    public LocalDate getPublishDate() {
+        return publishDate;
+    }
+
+    public void setPublishDate(LocalDate publishDate) {
+        this.publishDate = publishDate;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        SchoolBook that = (SchoolBook) o;
+        return Objects.equals(authorName, that.authorName) &&
+                Objects.equals(authorLastName, that.authorLastName) &&
+                Objects.equals(publishDate, that.publishDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), authorName, authorLastName, publishDate);
+    }
+
+    @Override
+    public String toString() {
+        return "SchoolBook{" +
+                "authorName='" + authorName + '\'' +
+                ", authorLastName='" + authorLastName + '\'' +
+                ", publishDate=" + publishDate +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java b/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java
new file mode 100644
index 00000000..769f16b1
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java
@@ -0,0 +1,53 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.Author;
+
+public class SimpleAuthorRepository implements AuthorRepository{
+    private Author[] authors = new Author[]{};
+
+    @Override
+    public boolean save(Author author) {
+        if (findByFullName(author.getName(), author.getLastName()) == null){
+            Author[] authors = new Author[this.count() + 1];
+            for (int i = 0; i < this.count() ; i++) {
+                authors[i] = this.authors[i];
+            }
+            authors[this.count()] = author;
+            this.authors = authors;
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastname) {
+        for (Author author:authors
+        ) {
+            if (author.getName().equals(name) && author.getLastName().equals(lastname)){
+                return author;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        if (findByFullName(author.getName(), author.getLastName()) != null){
+            Author[] authors = new Author[this.count() - 1];
+            int j = 0;
+            for (int i = 0; i < this.count()-1; i++) {
+                if( !(author.getName().equals(this.authors[i].getName()) && author.getLastName().equals(this.authors[i].getLastName())) ) {
+                    authors[j++] = this.authors[i];
+                }
+            }
+            this.authors = authors;
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public int count() {
+        return authors.length;
+    }
+}
diff --git a/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java b/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java
new file mode 100644
index 00000000..5770f294
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java
@@ -0,0 +1,76 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.entity.Book;
+import com.epam.izh.rd.online.entity.SchoolBook;
+
+import java.lang.reflect.Array;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Stream;
+
+public class SimpleSchoolBookRepository implements BookRepository<SchoolBook>{
+    private SchoolBook[] schoolBooks = new SchoolBook[]{};
+
+
+    @Override
+    public boolean save(SchoolBook book) {
+        if (book != null){
+            SchoolBook[] schoolBooks = new SchoolBook[this.schoolBooks.length + 1];
+            for (int i = 0; i < this.schoolBooks.length ; i++) {
+                schoolBooks[i] = this.schoolBooks[i];
+            }
+            schoolBooks[this.schoolBooks.length] = book;
+            this.schoolBooks = schoolBooks;
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public SchoolBook[] findByName(String name) {
+        int countOfFoundSchoolBooks = 0;
+        for (SchoolBook schoolBook: schoolBooks
+        ) {
+            if (schoolBook.getName().equals(name)){
+                countOfFoundSchoolBooks++;
+            }
+        }
+
+        SchoolBook[] foundSchoolBooks = new SchoolBook[countOfFoundSchoolBooks];
+
+        int j = 0;
+        for (SchoolBook schoolBook: schoolBooks
+        ) {
+            if (schoolBook.getName().equals(name)){
+                foundSchoolBooks[j++] = schoolBook;
+            }
+        }
+
+        return foundSchoolBooks;
+    }
+
+    @Override
+    public boolean removeByName(String name) {
+        int amountOfFoundBooks = this.findByName(name).length;
+        if( amountOfFoundBooks != 0){
+            SchoolBook[] schoolBooks = new SchoolBook[this.count() - amountOfFoundBooks];
+            int i = 0;
+            for (SchoolBook schoolBook: this.schoolBooks
+            ) {
+                if (!schoolBook.getName().equals(name)){
+                    schoolBooks[i++] = schoolBook;
+                }
+            }
+            this.schoolBooks = schoolBooks;
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public int count() {
+        return schoolBooks.length;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java
new file mode 100644
index 00000000..991a7ef2
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java
@@ -0,0 +1,36 @@
+package com.epam.izh.rd.online.service;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.repository.AuthorRepository;
+
+public class SimpleAuthorService implements AuthorService{
+
+    private AuthorRepository authorRepository;
+
+    @Override
+    public boolean save(Author author) {
+        return authorRepository.save(author);
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastName) {
+        return authorRepository.findByFullName(name, lastName);
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        return authorRepository.remove(author);
+    }
+
+    @Override
+    public int count() {
+        return authorRepository.count();
+    }
+
+    public SimpleAuthorService() {
+    }
+
+    public SimpleAuthorService(AuthorRepository authorRepository) {
+        this.authorRepository = authorRepository;
+    }
+}
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java
new file mode 100644
index 00000000..96612a49
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java
@@ -0,0 +1,60 @@
+package com.epam.izh.rd.online.service;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.entity.Book;
+import com.epam.izh.rd.online.entity.SchoolBook;
+import com.epam.izh.rd.online.repository.BookRepository;
+
+public class SimpleSchoolBookService implements BookService<SchoolBook>{
+
+    private BookRepository<SchoolBook> schoolBookBookRepository;
+    private AuthorService authorService;
+
+    public SimpleSchoolBookService() {
+    }
+
+    public SimpleSchoolBookService(BookRepository<SchoolBook> schoolBookBookRepository, AuthorService authorService) {
+        this.schoolBookBookRepository = schoolBookBookRepository;
+        this.authorService = authorService;
+    }
+
+    @Override
+    public boolean save(SchoolBook book) {
+        if(authorService.findByFullName(book.getAuthorName(), book.getAuthorLastName()) != null)
+        {
+            schoolBookBookRepository.save(book);
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public SchoolBook[] findByName(String name) {
+        return schoolBookBookRepository.findByName(name);
+    }
+
+    @Override
+    public int getNumberOfBooksByName(String name) {
+        return schoolBookBookRepository.findByName(name).length;
+    }
+
+    @Override
+    public boolean removeByName(String name) {
+        return schoolBookBookRepository.removeByName(name);
+    }
+
+    @Override
+    public int count() {
+        return schoolBookBookRepository.count();
+    }
+
+    @Override
+    public Author findAuthorByBookName(String name) {
+        if ( schoolBookBookRepository.findByName(name).length != 0 ){
+            SchoolBook schoolBook = schoolBookBookRepository.findByName(name)[0];
+            Author author = authorService.findByFullName(schoolBook.getAuthorName(),schoolBook.getAuthorLastName());
+            return author;
+        }
+        return null;
+    }
+}