MLA

Shackelford, Todd K, Nicholas Pound, and Todd Kennedy Shackelford. Sperm Competition In Humans. Springer US, 2006.

APA

Shackelford, T. K, Pound, N., & Shackelford, T. Kennedy. (2006). Sperm Competition in Humans. Springer US.

Chicago

Shackelford, Todd K., Nicholas Pound, and Todd Kennedy Shackelford. Sperm Competition In Humans. : Springer US, 2006.