diff --git a/README.md b/README.md
index 8db8fc1..c71c641 100644
--- a/README.md
+++ b/README.md
@@ -30,3 +30,6 @@ Try following:
 5. https://code.google.com/archive/p/uthm-thesis-lyx/
 6. https://github.com/klenje/unibo-thesis-lyx
 7. https://github.com/kks32/PhDThesisLyX
+ 
+## Useful resources
+1. http://www.ncbi.nlm.nih.gov/books/NBK988/