diff --git a/scibot/extract.py b/scibot/extract.py
index 86b26ff..d380bde 100644
--- a/scibot/extract.py
+++ b/scibot/extract.py
@@ -329,11 +329,14 @@ def find_rrids(text):
     regex3 = '(.{0,32})(BDSC|BL|Bl|Bloomington)(\s?)(stock)?(\s)?(#|no|no\.)?(\s?)([0-9]{2,10})([^\w].{0,31})'
     matches3 = re.findall(regex3, text)
     for prefix, a, b, c, d, e, f, nums, suffix in matches3:
+        if nums in ['17', '21']:
+            # special case to avoid false positives
+            continue
         yield prefix, f'RRID:BDSC_{nums.strip()}', f'{a}{b}{c}{d}{e}{f}{nums}', suffix
 
     # fourth round for SAMN
     regex4 = '(.{0,32})(SAMN)(\s?)([0-9]{3,15})([^\w].{0,31})'
-    matches4 = re.findall(regex3, text)
+    matches4 = re.findall(regex4, text)
     for prefix, a, b, nums, suffix in matches4:
         yield prefix, f'RRID:SAMN{nums.strip()}', f'{a}{b}{nums}', suffix