Zygmunt Rybicki: Rady delegatów robotniczych w Polsce 1918-1919, Warszawa 1962, PWN. Contemporary Central & East European Law, [S. l.], n. 2, p. 17–18, 1963. Disponível em: https://czasopisma.inp.pan.pl/index.php/cceel/article/view/1645. Acesso em: 8 oct. 2025.