diff --git a/CITATION.bib b/CITATION.bib
index 548190c..3e53901 100644
--- a/CITATION.bib
+++ b/CITATION.bib
@@ -6,3 +6,37 @@ @uni-siegen.de>
 	year    = {2025},
 	month   = {1}
 }
+
+@article {BR,
+    AUTHOR = {Barakat, Mohamed and Robertz, Daniel},
+     TITLE = {$\mathtt{homalg}$ -- {A} meta-package for homological algebra},
+   JOURNAL = {J. Algebra Appl.},
+  FJOURNAL = {Journal of Algebra and its Applications},
+    VOLUME = {7},
+      YEAR = {2008},
+    NUMBER = {3},
+     PAGES = {299--317},
+      ISSN = {0219-4988},
+   MRCLASS = {16E30 (16-04)},
+  MRNUMBER = {2431811 (2009f:16010)},
+MRREVIEWER = {Mikael Vejdemo Johansson},
+       DOI = {10.1142/S0219498808002813},
+       URL = {https://dx.doi.org/10.1142/S0219498808002813},
+      note = {(\href{http://arxiv.org/abs/math.AC/0701146}{\texttt{arXiv:math.AC/0701146}})},
+}
+
+@article{BL,
+    AUTHOR = {Barakat, Mohamed and Lange-Hegermann, Markus},
+  keywords = {BarakatReviewed},
+     TITLE = {An axiomatic setup for algorithmic homological algebra and an alternative approach to localization},
+   JOURNAL = {J.~Algebra Appl.},
+  FJOURNAL = {Journal of Algebra and its Applications},
+    VOLUME = {10},
+      YEAR = {2011},
+    NUMBER = {2},
+     PAGES = {269--293},
+   MRCLASS = {18E10 (18E25)},
+  MRNUMBER = {2795737 (2012f:18022)},
+  DOI = {10.1142/S0219498811004562},
+  URL = {https://dx.doi.org/10.1142/S0219498811004562},
+}
diff --git a/README.md b/README.md
index 0c3cc40..a4910d6 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+<!-- BEGIN HEADER -->
 # MatricesForHomalg
 
 ### Matrices for the homalg project
@@ -7,6 +8,35 @@
 [![Build Status](https://github.com/homalg-project/MatricesForHomalg.jl/actions/workflows/Tests.yml/badge.svg?branch=main)](https://github.com/homalg-project/MatricesForHomalg.jl/actions/workflows/Tests.yml?query=branch%3Amain)
 [![Coverage](https://codecov.io/gh/homalg-project/MatricesForHomalg.jl/branch/main/graph/badge.svg)](https://codecov.io/gh/homalg-project/MatricesForHomalg.jl)
 
+<!-- END HEADER -->
+
+This package implements the homalg matrix interface in Julia. The
+corresponding GAP package [MatricesForHomalg][MatricesForHomalg] is
+used by the projects:
+
+* [homalg project][homalg project],
+* [CAP project][CAP project],
+* [CategoricalTowers][CategoricalTowers],
+* [HigherHomologicalAlgebra][HigherHomologicalAlgebra].
+
+We are gradually creating Julia-versions of the various GAP packages
+in these projects and many of them will rely on this package.
+
+The current version only supports matrices over $\mathbb{Z}$ and
+$\mathbb{Q}$. Matrices over [Bézout domains][Bézout domains] will be
+supported next. Future versions should cover the full functionality of
+the GAP package [MatricesForHomalg][MatricesForHomalg] by supporting
+matrices over so-called computable rings [[BR][BR], [BL][BL]].
+
 ## Citing
 
 See [`CITATION.bib`](CITATION.bib) for the relevant reference(s).
+
+[MatricesForHomalg]: https://homalg-project.github.io/pkg/MatricesForHomalg/
+[CAP project]: https://homalg-project.github.io/prj/CAP_project/
+[homalg project]: https://homalg-project.github.io/prj/homalg_project/
+[CategoricalTowers]: https://homalg-project.github.io/prj/CategoricalTowers/
+[HigherHomologicalAlgebra]: https://homalg-project.github.io/prj/HigherHomologicalAlgebra/
+[Bézout domains]: https://ncatlab.org/nlab/show/B%C3%A9zout+domain
+[BR]: https://arxiv.org/abs/math/0701146
+[BL]: https://arxiv.org/abs/1003.1943