Cita APA (7a ed.)

Kowalczyk, J. J. (1917). Prussian - Poland: A stronghold of German militarism. [s.n.].

Cita Chicago Style (17a ed.)

Kowalczyk, Jan Jakub. Prussian - Poland: A Stronghold of German Militarism. Copenhagen: [s.n.], 1917.

Cita MLA (9a ed.)

Kowalczyk, Jan Jakub. Prussian - Poland: A Stronghold of German Militarism. [s.n.], 1917.