diff --git a/content/3.defense-systems/abia.md b/content/3.defense-systems/abia.md
index fffc9c8ac33817bd94e06d560b1d7e3af5329556..912ea20db0b48724cc3d72306c6071bd0671ad41 100644
--- a/content/3.defense-systems/abia.md
+++ b/content/3.defense-systems/abia.md
@@ -26,7 +26,7 @@ AbiA_small subsystem in the genome of *Mesobacillus foraminis* (GCF_003667765.1)
 
 ## Distribution of the system among prokaryotes 
 
-The AbiA system is present in a total of 35 different species :ref{doi=10.1023/A:1002027321171}.
+The AbiA system is present in a total of 35 different species.
 
 
 
@@ -77,7 +77,6 @@ items:
     - doi: 10.1023/A:1002027321171
     - doi: 10.1016/j.mib.2005.06.006
     - doi: 10.1093/nar/gkac467
-
 ---
 ::