Mann, Prem S.
New York John Wiley & Sons 1995,
Buku Teks
Kazmier, Leonard J.
McGraw-Hill, 1984
Buku Teks SO
Shao, Stephen P.
Virginia s.n,
Buku Teks SO
Berenson, Mark L.
Prentice-Hall, 1993
Buku Teks SO
Hoel, Paul Gerhard, 1905-
Wiley, 1982
Buku Teks SO