Hannan, E.J.
John Wiley, 1970
Buku Teks
edited by G. Louchard and G. Latouche
Academic Press, 1983
Buku Teks
Rohatgi, V.K.
John Wiley & Sons, 1976
Buku Teks
Mendenhall, William
Wadsworth , 1967
Buku Teks
Hoffmann-Jorgensen, J.
Chapman & Hall, 1994
Buku Teks