P. Augerstein, Der Konflikt des polnischen Konigs Boleslaw II.
According to Nitschmann in his Geschichte der polnischen - Litteratur - a work which has been of service in the preparation of this article - the books were transported to Russia very carelessly, and many of them injured by the way.
- Pipin and Spafovich, Istoria slavianskikh Literatur (in Russian; St Petersburg, 1879); Geschichte der polnischen Literatur von Dr A.
Bruckner (Leipzig, 1901; also written in Polish); Chmielowski, History of Polish Literature (in Polish, 3 vols.); Stanislaus Tarnowski, History of Polish Literature (in Polish); Grabowski, Poezya Polska po roku 1863 (Cracow, 1903); Heinrich Nitschmann, Geschichte der polnischen Literatur (Leipzig; sine anno).