MTP Press , 1980
Buku Teks
Waugh, Albert E., author
McGraw-Hill, 1952
Buku Teks
Samuel, Myra L., author
Pearson - Prentice Hall, 2003
Buku Teks
Schork, M. Anthony, author
Prentice-Hall, 2000
Buku Teks
Dunn, Olive Jean, author
John Wiley & Sons, 1977
Buku Teks