Sinclair, U., & Downs, R. B. (1960). The jungle: Upton Sinclair. With an afterw. by Robert B. Downs (20. print.). New American Library.

Sinclair, Upton, and Robert B. Downs. The Jungle: Upton Sinclair. With an Afterw. by Robert B. Downs. 20. print. New York: New American Library, 1960.

Sinclair, Upton, and Robert B. Downs. The Jungle: Upton Sinclair. With an Afterw. by Robert B. Downs. 20. print. New American Library, 1960.