Still, Richard R.
Prentice Hall International, 1988
Buku Teks
Storholm, Gordon R.
Prentice-Hall, 1982
Buku Teks SO
Spiro, Rosann L.
McGraw-Hill-Irwin, 2003
Buku Teks SO
Stanton, William J.
Richard D. Irwin, 1978
Buku Teks SO
Voe, Merrill De
Prentice-Hall, 1957
Buku Teks SO