Haskell, Martin R.
Rand McNally College, 1974
Buku Teks
Pusat Penelitian Pranata Pembangunan UI , 1990
Buku Teks
Silbermaan, Charles E., author
Random House, 1978
Buku Teks
Wright, Burton, author
W.B. Saunders, 1978
Buku Teks
Jones, Howard, author
Penguin Books, 1965
Buku Teks