Doll, John P.
John Wiley & Sons, 1984
Buku Teks
Heady, Earl O., author
Prentice-Hall, 1952
Buku Teks
Black, John Donald
Macmillan, 1953
Buku Teks
Beattie, Bruce R., author
Gadjah Mada University Press, 1994
Buku Teks
Martin, Anne
Routledger Kegan Paul , 1958
Buku Teks