In 1791, Johann Gerstenberg opened the biggest publishing company which Friedrich Dittmar took over from him and which successively became Johann Poetsch's, Klewer's, Stellowsky's and Gutheil's property. Bernhard Breitkopf worked in Russia as from 1793 and in collaboration with Reinsdorp and Lehnhold published music in Moscow. The imprint of title pages in music prints of the 18th and the first half of the 19th century are often incomplete or entirely missing. For more than 30 years, within the department for music editions of the Russian National Library a card index of the printing plates of Russian and foreign editions and prints has been built up containing the names of the publishers and printers as well as the date of the printing plate. This card index served as the basis of the work on the joint catalogue.
Problems appear in registering theatre music editions.
Only a small number of music theatre works have been handed down, contrary to the numerous existing announcements of opera editions. Investigations showed that these announcements refer to the libretti, not to the piano arrangements of the operas. Often the librettist is mentioned as author of the opera which has sometimes lead to errors in naming the composer. The majority of 18th century opera libretti were not written for stage performance but as a drama for reading. These melodies were known to everyone and did not need printing.