Cita APA (7th ed.)

Sauvy, J., & Sauvy, S. (1974). The child's discovery of space. Penguin Educaction.

Cita Chicago (17th ed.)

Sauvy, Jean, i Simonne Sauvy. The Child's Discovery of Space. Harmondsworth, Eng.: Penguin Educaction, 1974.

Cita MLA (9th ed.)

Sauvy, Jean, i Simonne Sauvy. The Child's Discovery of Space. Penguin Educaction, 1974.