Stonier, Alfred W.
Ghallia Indonesia, 1984
Buku Teks
Hague, Douglas C.
Longmans, Green and Co., 1955
Buku Teks
Nevin, Edward
Macmillan ; St. Martin's Press, 1960
Buku Klasik
Mehta, J.K.
Caitanya Publishing House, 1967
Buku Teks
Blaug, Mark
Cambridge University Press, 1987
Buku Teks