Leedy, P. D. (1980). Practical research: Planning and Desgn (2nd ed.). Macmillan.
Chicago Style (17th ed.) ZitazioaLeedy, Paul D. Practical Research: Planning and Desgn. 2nd ed. New York: Macmillan, 1980.
MLA (9th ed.) ZitazioaLeedy, Paul D. Practical Research: Planning and Desgn. 2nd ed. Macmillan, 1980.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.