Hunt, Pearson, author
Richard D. Irwin, [Date of publication not identified]
Buku Teks
Rudden, Bernard, author
Clarendon Press, 1987
Buku Teks
Velasquez, Manuel G., author
Pearson, 2006
Buku Teks
Johnson, Rossall James, 1917-, author
LPEM - FEUI, 1961
Buku Teks
Handler, Milton
University Casebook, 1972
Buku Teks