Nowak, S., & Lepa, M. O. (1977). Methodology of sociological research: General problems. PWN-Polish Scientific Publishers ; D. Reidel Publishing Company.
Citazione stile Chigago Style (17a edizione)Nowak, Stefan, e Maria Olga Lepa. Methodology of Sociological Research: General Problems. Warszawa : Dordrecht ; Boston: PWN-Polish Scientific Publishers ; D. Reidel Publishing Company, 1977.
Citatione MLA (9a ed.)Nowak, Stefan, e Maria Olga Lepa. Methodology of Sociological Research: General Problems. PWN-Polish Scientific Publishers ; D. Reidel Publishing Company, 1977.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.