From the website:

"The “Index to Yiddish Periodicals” is a bibliographical data base using Yiddish, which aims to record the materials published in the Yiddish press.
This ongoing bibliographical project is carried out under the auspices of the Yiddish Department at the Hebrew University of Jerusalem in cooperation with the Jewish National and University Library.

This bibliographical data base includes all signed materials, whether they carry the real name of their author or a pseudonym. It doesn’t register unsigned news or articles, except when these deal with issues related to Yiddish literature and culture.

The ALEPH search interface gives the user numerous options to browse the data base: name of author, title, source, date, genre (for literary works), subject (for journalistic articles).

The thematic index in particular allows the browser to reach the wealth of information published in the Yiddish press, especially about Jewish communities in Eastern Europe and abroad, political and cultural Jewish movements, institutions, Yiddish and Hebrew writers and actors, trends in all fields of Jewish Culture. The thematic index registers materials published in the Yiddish press about general subjects as well."