Cita APA

Helen, Helen Mellanby, & Helen Mellanby. (1953). Animal life in freshwater (5.). London.

Citación estilo Chicago

Helen, Helen Mellanby, y Helen Mellanby. Animal Life in Freshwater. 5. London, 1953.

Cita MLA

Helen, et al. Animal Life in Freshwater. 5. London, 1953.