APA (7th ed.) Citation

Marshak, S., & Prothero, D. Portrait of a Planet: Stephen Marshak. c2001.

Chicago Style (17th ed.) Citation

Marshak, Stephen, and Donald Prothero. Portrait of a Planet: Stephen Marshak. W. W. Norton & Company: c2001.

MLA (9th ed.) Citation

Marshak, Stephen, and Donald Prothero. Portrait of a Planet: Stephen Marshak. c2001.