Cita APA (7a ed.)

Christie, J. F., & Johnsen, E. P. (1989). The constraints of settings on children's play. [s.n.].

Cita Chicago Style (17a ed.)

Christie, James F., y E. Peter Johnsen. The Constraints of Settings on Children's Play. [S.l.]: [s.n.], 1989.

Cita MLA (9a ed.)

Christie, James F., y E. Peter Johnsen. The Constraints of Settings on Children's Play. [s.n.], 1989.