Cita APA (7th ed.)

Gray, G., & Guppy, N. (2003). Successful Surveys: Research Methods and Practice (3rd ed.). Thomson Nelson.

Cita Chicago (17th ed.)

Gray, George, i Neil Guppy. Successful Surveys: Research Methods and Practice. 3rd ed. Scarborough: Thomson Nelson, 2003.

Cita MLA (9th ed.)

Gray, George, i Neil Guppy. Successful Surveys: Research Methods and Practice. 3rd ed. Thomson Nelson, 2003.