Cita APA (7a ed.)

Tharp, R. G., & Wetzel, R. J. (1969). Behavior modification in the natural environment. Academic Press.

Cita Chicago Style (17a ed.)

Tharp, Roland G., y Ralph J. Wetzel. Behavior Modification in the Natural Environment. New York [etc.]: Academic Press, 1969.

Cita MLA (9a ed.)

Tharp, Roland G., y Ralph J. Wetzel. Behavior Modification in the Natural Environment. Academic Press, 1969.