Fischer, Fritz
Germany's aims in the first world war
W.W. Norton, 1967
 Buku Teks SO
Adelman, M.A.
The world petroleum market
Johns Hopkins University Press, 1972
 Buku Teks
Fischer, Fritz
World power or decline: the controversy over Germany's aims in the first world war
W.W. Norton, 1974
 Buku Teks SO
Heijbroek, A.M.A.
The world seed market : developments and strategies
Rabobank International Group , 1996
 Buku Teks SO
Heijbroek, A.M.A.
The world seed market : developments and strategies
Rabobank International Group , 1996
 Buku Teks SO