Hannah, John
Longman Scientific & Technical, 1993
Buku Teks SO
Singer, Ferdinand L.
New York: Harper and Row, 1975
Buku Teks
Meriam, James L.
John Wiley & Sons, 1978
Buku Teks SO
Meriam, James L.
John Wiley & Sons, 1959
Buku Teks SO
Poorman, Alfred P.
McGraw-Hill , 1949
Buku Teks SO