William H.Kaempter
McGraw-Hill, 1995
Buku Teks
Chacholiades, Miltiades, author
McGraw-Hill, 1978
Buku Teks
edited by Roy Harrod
Martin Press, 1965
Buku Teks
Johnson, Harry G., author
George Allen and Unwin, 1958
Buku Teks
Viner, Jacob, author
George Allen and Unwin, 1960
Buku Teks