 These identified, mostly for the first time, thousands of previously unrecognized and undocumented synagogues, churches, mosques, cemeteries and Holocaust-related sites, almost all of which were visited and by survey teams that described their condition.These projects included full or partial surveys of Jewish sites in Bosnia and Herzegovina, Bulgaria, The Czech Republic, Estonia, Hungary, Latvia, Lithuania, Moldova, Poland, Romania, Slovakia, Slovenia, and Ukraine; Roma sites in Poland; Old Believers sites in Lithuania; and Protestant Christian and Muslim sites in Bulgaria.He is author or editor of numerous articles and survey reports about Jewish monuments, and is a frequent public lecturer in the United States and Europe.