Arnold, H.J.P., author
Dufour Editions, 1966
Buku Teks
Benham, Frederic, author
Oxford University Press, 1962
Buku Teks
International Bank for Reconstruction and Development
World Bank, 1994
Buku Teks
Thorp, Willard L., author
Organisation for Economic Co-operation and Development , 1964
Buku Teks
by H.B. Chenery ... [et al.]
Universitaire Pers Rotterdam, 1967
Buku Teks