Cita APA (7a ed.)

Lucas, J., & McKennell, V. (1974). The Penguin book of playgroups. Penguin Books.

Cita Chicago Style (17a ed.)

Lucas, Joyce, y Vivienne McKennell. The Penguin Book of Playgroups. Harmondsworth ; Baltimore: Penguin Books, 1974.

Cita MLA (8a ed.)

Lucas, Joyce, y Vivienne McKennell. The Penguin Book of Playgroups. Penguin Books, 1974.