In the same year he joined the staff of the Hermitage Museum in Leningrad (now Saint Petersburg). In 1949 he published a comprehensive study of Assyria, followed in 1956 by a monograph on Media. Later on, he teamed up with the linguist Sergei Starostin to produce authoritative studies of the Caucasian, Afroasiatic, and Hurro-Urartian languages.