Nemmers, Erwin Esser
Littlefield, Adam and Co., 1960
Buku Teks
Velasquez, Manuel G.
Pearson, 2006
Buku Teks
Johnson, Rossall James, 1917-
LPEM - FEUI, 1961
Buku Teks
Handler, Milton
University Casebook, 1972
Buku Teks
Wyat, John W.
McGraw-Hill, 1963
Buku Teks