Buku Teks
Bronfenbrenner, Martin, author
Illinois, 1987
Buku Teks
McConnell, Campbell R., author
[publisher not identified], [date of publication not identified]
Buku Teks
Samuelson, Paul A. (Paul Anthony), 1915-2009, author
McGraw-Hill, 1970
Buku Teks
Lipsey, Richard G., 1928-, author
HarperCollinsCollege Publishers, 1996
Buku Teks