Cita APA (7th ed.)

Eckhardt, K. W., & Ermann,M.David. (1977). Social research methods: Perspective theory and analysis. Randon.

Cita Chicago (17th ed.)

Eckhardt, Kenneth W., i Ermann,M.David. Social Research Methods: Perspective Theory and Analysis. New York: Randon, 1977.

Cita MLA (9th ed.)

Eckhardt, Kenneth W., i Ermann,M.David. Social Research Methods: Perspective Theory and Analysis. Randon, 1977.