Blum, Julius R.
W.B. Saunders, 1972
Buku Teks
Ugarte, Maria Dolores
CRC Press, Taylor & Francis Group, 2008
Buku Teks
Alder, Henry L.
W H Freeman, 1968
Buku Teks
Walpole, Ronald E.
Macmillan, 1972
Buku Teks
Mendenhall, William
Wadsworth , 1967
Buku Teks