Polish Research Centre (Londyn). (1942). German failures in Poland: Natural obstacles to Nazi population policy. Polish Research Centre.
Citazione stile Chigago Style (17a edizione)Polish Research Centre (Londyn). German Failures in Poland: Natural Obstacles to Nazi Population Policy. London: Polish Research Centre, 1942.
Citatione MLA (9a ed.)Polish Research Centre (Londyn). German Failures in Poland: Natural Obstacles to Nazi Population Policy. Polish Research Centre, 1942.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.