Cita APA (7a ed.)

Mills, S. (1991). The essential book of herbal medicine. Penguin Books.

Cita Chicago Style (17a ed.)

Mills, Simon. The Essential Book of Herbal Medicine. London: Penguin Books, 1991.

Cita MLA (9a ed.)

Mills, Simon. The Essential Book of Herbal Medicine. Penguin Books, 1991.