Waugh, Albert E.
McGraw-Hill, 1952
Buku Teks SO
Samuel, Myra L.
Pearson - Prentice Hall, 2003
Buku Teks
Schork, M. Anthony
Prentice-Hall, 2000
Buku Teks
Dunn, Olive Jean
John Wiley & Sons, 1977
Buku Teks
Daniel, Wayne W.
John Wiley & Sons, 1983
Buku Teks