Cita APA (7a ed.)

Roberts, K. L., & Roberts, K. (1970). Leisure. Longman.

Cita Chicago Style (17a ed.)

Roberts, Kenneth L., y Kenneth Roberts. Leisure. London: Longman, 1970.

Cita MLA (9a ed.)

Roberts, Kenneth L., y Kenneth Roberts. Leisure. Longman, 1970.