Davies, Ivor K., author
McGraw-Hill, 1981
Buku Teks
Sutton, Kelso, author
McGraw-Hill, 1949
Buku Teks
The Lancet, 1928"
Buku Teks
Atkinson, Lucky Jo, author
Mosby , 1995
Buku Teks
prepared by the Committee on Marketing Research Techniques of the American Marketing Society ; Ferdinand C. Wheeler, chairman
McGraw-Hill, 1937
Buku Teks