Rosenberg, Jerry M.
John Wiley & Sons, 1995
Buku Referensi
Kelley, Pearce Clement
Prentice-Hall, 1957
Buku Teks
Cahill, Jane.
Fairchild Publications , 1960
Buku Teks
Hollander, Stanley C.
Michigan State University , 1960
Buku Teks
Scott, Peter
Huytchinson University Library , 1970
Buku Teks