Given the explain record at the other end of the following URL, how do I query the Library of Congress for an ISBN number: http://z3950.loc.gov:7090/voyager For example, I see the following in the explain output but I don't know how to turn that into a query: <index id="7"> <title>isbn</title> <map><name set="bath">isbn</name></map> </index> Something like this returns an "Unsupported index" error: http://z3950.loc.gov:7090/voyager? operation=searchRetrieve&version=1.1&query=isbn=0300077491 -- Eric "Feeling Embarrassed" Morgan University Libraries of Notre Dame (574) 631-8604