Pike, William H.
Dow Joner-Irwin, 1983
Buku Teks
McGraw-Hill, 2012
Buku Referensi
William Irwin, George A. Dunn
Wiley Blackwell, cop, 2014
Buku Teks
Cohn, Elizabeth Gross, author
W.B. Saunders, 2002
Buku Teks
West, Jessamyn
Harcourt, Brace and Co., 1957
Buku Teks