APA (7th ed.) Citation

Koch, H. L. (1966). Twins and twin relations. Univ. of Chicago Press.

Chicago Style (17th ed.) Citation

Koch, Helen L. Twins and Twin Relations. Chicago: Univ. of Chicago Press, 1966.

MLA (9th ed.) Citation

Koch, Helen L. Twins and Twin Relations. Univ. of Chicago Press, 1966.

Warning: These citations may not always be 100% accurate.