Cita APA (7a ed.)

Ward, B. (1972). Only One Earth: The care and maitenance of a small planet. Penguin Book.

Cita Chicago Style (17a ed.)

Ward, Barbara. Only One Earth: The Care and Maitenance of a Small Planet. Great Britain: Penguin Book, 1972.

Cita MLA (8a ed.)

Ward, Barbara. Only One Earth: The Care and Maitenance of a Small Planet. Penguin Book, 1972.