Cita APA (7th ed.)

Petersen, M. S., & Rigby, J. K. (1999). Interpreting earth history: A manual in historical geology (6th ed.). WCB/McGraw-Hill.

Cita Chicago (17th ed.)

Petersen, Morris S., i J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 6th ed. Boston: WCB/McGraw-Hill, 1999.

Cita MLA (9th ed.)

Petersen, Morris S., i J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 6th ed. WCB/McGraw-Hill, 1999.