Cita APA (7th ed.)

Petersen, M. S., & Rigby, J. K. (1990). Interpreting earth history: A manual in historical geology (4th ed.). Wm. C. Brown Publishers.

Cita Chicago (17th ed.)

Petersen, Morris S., i J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 4th ed. Dubuque, U.S.A: Wm. C. Brown Publishers, 1990.

Cita MLA (9th ed.)

Petersen, Morris S., i J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 4th ed. Wm. C. Brown Publishers, 1990.