Bibliografia Polska Estreicherów a digitalizacja katalogów i zbiorów bibliotek rosyjskich, ukraińskich, białoruskich i litewskich. Kilka spostrzeżeń z perspektywy redaktora: nowe wyzwania i rozwój metodologii

The shape and content of the newly edited volumes of the Estreicher Family Polish Bibliography (namely vol. 19 and 20 of the new edition of the Polish Bibliography of the 19th century) were strongly affected by the accelerated pace of digitization of catalogues and collections of the Russian, Ukrainian, Belarusian and Lithuanian libraries. Digital access to these re- sources allowed our team to locate many previously unknown Polish books, but the vast amount of data required a practical strategy of quick and effective searching. Moreover, the criteria of selection became an important methodological concern: both the specific characteristics of the newly surfaced materials and recent studies dealing with participation of Polish people in the cultural and academic life of the neighbouring nations show that the Polish heritage includes numerous books in Russian (and other languages as well), e.g. the publications of the Polish scientists who worked in the Russian Empire. Discovering and documenting such unobvious parts of Polish heritage become one of the fundamental tasks for the present-day researchers.