Gaya APA
Leroy, L, W. et al (1977).
Subsurface Geology:Petroleum Mining Construction (Ed.2).
USE,. New York London:
Libraries Unlimited.
Gaya MLA
Leroy, L., W.. et al.
"Subsurface Geology:Petroleum Mining Construction".
Ed.2
USE,. New York London:
Libraries Unlimited,
1977.
Buku TP.