Scott, Ewing C.
Harper & Row, 1962
Buku Teks
Timberlake, Karen C., author
Prentice-Hall, 2007
Buku Teks
Suchocki, John, author
Pearson Benjamin Cummings, 2007
Buku Teks
Whitten, Kenneth W., author
Saunders College, 1992
Buku Teks
Umland, Jean B., author
Brooks/Cole, 1999
Buku Teks