Maybe this topic has been handled in the past, but I'm curious about techniques others use to locate numismatic (and other) literature for sale on the internet. Presumably everyone knows how to use Google and to search eBay and large retailers such as Amazon and Barnes & Noble. But which English-language multi-dealer search site works best, and which are the best foreign language sites?

When I sell out of a worthy title at my own site I remove the price and substitute a "FIND IT" link to a links page with my own favorites. My top recommendation is www.addall.com/Used/ and I occasionally use others such as: www.usedbooksearch.co.uk/cgi/search.cgi , www.bookfinder.com , and www.abebooks.com/servlet/SearchEntry .

I haven't had much luck finding either foreign or English language titles at sites dedicated to French, Spanish, German, and other language sites, but wonder what other readers might recommend.