Literary and artistic estates and bequests, archives and individual autographs serve as unique sources for literary and art research, for example by allowing the process of the genesis of a work to be traced through the various preserved textual stages or stages of creation. Pre- and posthumous materials also provide an irreplaceable basis for biographical and cultural-historical research as well as for interdisciplinary questions, edition projects or exhibitions. The International Youth Library holds the bequests and partial bequests described below.