 His more renowned second monograph, "Jews in Poland-Lithuania in the Eighteenth Century" (2004), is an essential revisionist work in early modern European Jewish historiography.It examines the life of the understudied, but extremely important, East Central European Jewry—world's largest Jewish community at the time, and argues for their "mentalité" of chosenness and their particularities on the path towards modernity.Another achievement is the groundbreaking "The YIVO Encyclopedia of Jews in Eastern Europe" published in 2008.