Gaya APA

Petersen, M, S., Rigby, J, K. (1994). Interpreting Earth History Historical Geology (Ed.4). : Wm. C. Brown.

Gaya MLA

Petersen, Morris, S.., Rigby, J., Keith. "Interpreting Earth History Historical Geology". Ed.4 : Wm. C. Brown, 1994. Buku TP.