The European Bibliography of Slavic and East European Studies (EBSEES) - 1991-2007

The European Bibliography of Slavic and East European Studies (EBSEES) collects books, journal articles, reviews and dissertations from Eastern Europe (former countries of Eastern Bloc) which were published in Belgium, Germany, Finland, France, Great Britain, the Netherlands, Austria and Switzerland from 1991 to 2007. The segment "Literature" and "Culture" of the European Bibliography of Slavic and East European Studies contains 18.000 bibliographic entries (from the total asset of 85.000). More information can be found here.

Your search for Sujecki, Janusz provides 2 hits
1	The relation of the Polish Socialist Party: Proletariat to the Bund and the Jewish Question, 1900-1906 Sujecki, Janusz, in: Polin, 9, 1996, p. 32-44
2	Praga - ein alter jüdischer Bezirk von Warschau Sujecki, Janusz, in: Das jüdische Echo 53, 2004, pp. 242-244

The European Bibliography of Slavic and East European Studies (EBSEES) - 1991-2007

The relation of the Polish Socialist Party: Proletariat to the Bund and the Jewish Question, 1900-1906

Praga - ein alter jüdischer Bezirk von Warschau