"The RISM Online Catalog is a free resource that can be accessed from www.rism.info and opac.rism.info. It documents manuscripts, printed music, libretti, and treatises. The online catalog contains all of series A/I, A/II, and years 1500-1550 of B/I. It is made possible through a partnership between the Bavarian State Library (Munich), the State Library of Berlin, and RISM. The Bavarian State Library is responsible for the operation and technical implementation of the RISM online catalog"-- http://www.rism.info/en/publications.html