MLA

Gershon, Michael D. The Second Brain : the Scientific Basis of Gut Instinct and a Groundbreaking New Understanding of Nervous Disorders of the Stomach and Intestine. New York, NY: HarperCollins Publishers, 1998.

APA

Gershon, M. D. (1998). The second brain : the scientific basis of gut instinct and a groundbreaking new understanding of nervous disorders of the stomach and intestine. New York, NY: HarperCollins Publishers.

Chicago

Gershon, Michael D. The Second Brain: The Scientific Basis of Gut Instinct and a Groundbreaking New Understanding of Nervous Disorders of the Stomach and Intestine. New York, NY: HarperCollins Publishers, 1998.