Frankel, P.H.
Chapman and Hall, 1946
Buku Teks
editor, John C. McCaslin
PennWell Publishing , 1990
Buku Referensi
Statistics Division, Petroleum Information Service, 1968
Buku Referensi
IPA.Petroleum Industry Management Forum , 1997
Buku Teks
Adelman, M.A.
Johns Hopkins University Press, 1972
Buku Teks