Wyat, John W.
McGraw-Hill, 1963
Buku Teks
Velasquez, Manuel G
Prentice-Hall, 2002
Buku Teks
Lusk, Harold F., 1893-, author
Richard D. Irwin, 1969
Buku Teks
Velasquez, Manuel G., author
Pearson, 2014
Buku Teks
Alt, Richard M., author
Richard D. Irwin, 1955
Buku Teks