American Economic Association
George Allen and Unwin, 1959
Buku Teks SO
Burke, Karen C., 1951-
West Publishing, 1992
Buku Teks SO
Burke, Karen C., 1951-
Thomson/West, 1999
Buku Teks SO
Gelfand, M. David
West Publishing, 1986
Buku Teks SO
Butters, J. Keith
Harvard University Press , 1951
Buku Teks SO