Redman, Deborah A.
Cambridge, Mass Massachusetts Institute of Technology 1997,
Buku Teks
Malthus, T.R.
N.Y. Kelley & Millman , 1954
Buku Teks
Robbins, Lionel Robbins, Baron, 1898-1984, editor
McMillan & Co., 1952
Buku Teks
Gurukkal, Rajan, author
Oxford University Press, 2016
eBooks
Byung-Nak Song, author
University Press, 2003
Buku Teks