Lange.Oskar. (1971). POLITICAL ECONOMY: PWN- POLISH SCIENTIFIC PUBLISHERS. WARSZAWA.
Čikaški stil citiranja (17. izdanje)Lange.Oskar. POLITICAL ECONOMY: PWN- POLISH SCIENTIFIC PUBLISHERS. panstwowe wydawnictwo naukowe: WARSZAWA, 1971.
MLA način citiranja (9. izdanje)Lange.Oskar. POLITICAL ECONOMY: PWN- POLISH SCIENTIFIC PUBLISHERS. WARSZAWA, 1971.