Sterling, T.D., author
Macmillan, 1970
Buku Teks
Van Duyn, Julia, author
John Wiley & Sons, 1982
Buku Teks
Van Duyn, Julia, author
John Wiley & Sons, 1982
Buku Referensi
Axelrod, C. Warren, author
John Wiley & Sons, 1982
Buku Teks
Axelrod, Warman, author
Prentice-Hall, 1982
Buku Teks