This is pretty random, but I happened across two patents that reference Kirupa tutorials:
http://www.patentstorm.us/patents/7151547.html
http://www.patentstorm.us/patents/7318202.html
(look in the ‘other references’ section)
Unfortunately, the patents are written in patent-ese, so I can’t really tell why the first one is relevant to the tutorial, but the second one is fairly self-explanatory.
+1 for the ubiquity of kirupa.com! :kommie:
