International Petroleum encyclopedia 1990
editor, John C. McCaslin
PennWell Publishing , 1990
 Buku Referensi
Horsnell, Paul
Oil markets and prices: the brent market and the formation of world oli prices
Oxford University Press, 1993
 Buku Teks
International petroleum encyclopedia 1996
editor Jim West
PennWell Pub. Co., 1998
 Buku Referensi
Frankel, P.H.
Essentials of petroleum : a key to oil economics
Chapman and Hall, 1946
 Buku Teks
Johnston, Daniel
International petroleum fiscal system and production sharing contracts
Penwell Books, 1994
 Buku Teks