Prof. Anna M. Cienciala (2004). "The Rebirth of Poland". History 557: Poland and Soviet Russia: 1917-1921. The Bolshevik Revolution, the Polish-Soviet War, and the establishment of the polish-soviet frontier. University of Kansas (Lecture Notes 11 B). Archived from the original on 2012-02-05. Diakses tanggal 31 July 2016 – via Internet Archive.Pemeliharaan CS1: Url tak layak (link)