Seth, M.L.
S. Chand, 1969
Buku Teks
Walker, E. Ronald
University of Chicago Press, 1947
Buku Teks
Harrod, R.F.
Macmillan, 1956
Buku Teks SO
Ropke, Wilhelm
Eugen Rentsch Verlag, 1961
Buku Teks
Baumol, William J.
Harper & Brother Publisher, 1954
Buku Teks