X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=tree_and_list_zippers.mdwn;h=1eb5d077972850c6adc72ff1e921d47fa2fa6e67;hp=ee627a7ef6095cbdd000aec661565bd43eefad4a;hb=d43f92cd1dbebb7588b856704bbd9c92b3031565;hpb=0feebbaaa58403d836d7ea6166cf709dd3faf1a8

diff --git a/tree_and_list_zippers.mdwn b/tree_and_list_zippers.mdwn
index ee627a7e..1eb5d077 100644
--- a/tree_and_list_zippers.mdwn
+++ b/tree_and_list_zippers.mdwn
@@ -247,6 +247,7 @@ where the targetted element is the root of our base tree. Like the "moving backw
 We haven't given you a real implementation of the tree zipper, but only a suggestive notation. We have however told you enough that you should be able to implement it yourself. Or if you're lazy, you can read:
 
 *	[[!wikipedia Zipper (data structure)]]
+*	[Haskell wikibook on zippers](http://en.wikibooks.org/wiki/Haskell/Zippers)
 *	Huet, Gerard. ["Functional Pearl: The Zipper"](http://www.st.cs.uni-sb.de/edu/seminare/2005/advanced-fp/docs/huet-zipper.pdf) Journal of Functional Programming 7 (5): 549-554, September 1997.
 *	As always, [Oleg](http://okmij.org/ftp/continuations/Continuations.html#zipper) takes this a few steps deeper.