Books (in Yiddish)
• Gzeyres Ta"kh [The Chmielnicki Massacres of 1648] (Vilnius: YIVO, 1938) • Yidishe bildungs-politik in Poyln fun 1806 biz 1866 [Jewish Educational Policy in Poland from 1806 to 1866] (New York: YIVO, 1943) • Geshikhte fun Yidn in Varshe [The History of the Jews in Warsaw] (3 volumes; New York: YIVO, 1947–1953) ==References==