The Morrison Collection - Dengmi Yadiao - Collection of 67 Chinese lantern riddles (in Chinese) with introduction, from a collection of Chinese books at SOAS. - http://www.babelstone.co.uk/Morrison/Texts/DengmiYadiao.html
Grecian Riddle-Jokes - Article by Evangelos Gr.Avdikos on riddle-jokes, which use word patching for parodying social situations. - http://folklore.ee/folklore/vol10/minorf.htm
Aenigmata - The early Medieval riddle collections by Symphosius and Aldhelm (in Latin), with an introduction. - http://personal.bgsu.edu/~jmpfund/Aenigmata.html
Homefun on Riddles - A guide to general questions about riddles, their significances, and forms. - http://www.siskiyous.edu/class/engl12/RIDDLES.htm
Sirandanes - Riddles - Riddles of Mauritia in Mauritian Creole, French and English. - http://www.kreol.mu/Sirandanes_1.htm
Old English Riddles - Paper by Hazel Brewer on the history of Old English riddles. - http://www.chass.utoronto.ca/~cpercy/courses/1001Brewer.htm
Yahoo! Groups: ClassicRiddles - Forum keeping the classic rhyming riddles alive. - http://groups.yahoo.com/group/ClassicRiddles/
Sexual Riddles: The Test of The Listener - Article by Annikki Kaivola-Bregenhøj discussing the history and context of sexual riddles. - http://cc.joensuu.fi/~loristi/1_97/kai197.html