diff --git a/governing the commons.md b/governing the commons.md
index be2bbbb5f..f4cc59695 100644
--- a/governing the commons.md	
+++ b/governing the commons.md	
@@ -1,3 +1,5 @@
 - a [[book]]
 	- by [[elinor ostrom]]
-	- 1992
\ No newline at end of file
+	- [[1990]]
+	- https://en.wikipedia.org/wiki/Special:BookSources/978-0-521-40599-7
+	- [[go]] https://books.google.ch/books?id=4xg6oUobMz4C&printsec=frontcover&dq=isbn:9780521405997&hl=en&sa=X&ved=2ahUKEwiU5ZfmhczwAhWEuaQKHVnnCEwQ6AEwAHoECAAQAg#v=onepage&q&f=false
\ No newline at end of file