Ensminger, Audrey; Ensminger, M.E.; Konlande, James E.; Robson, John R.K.
CRC Press, 1994
Buku Referensi
Werbach, Melvyn R., author
Thorsons, 1993
Buku Referensi
Murray, Michael T., author
Three Rivers Press, 1996
Buku Teks
Stevenson, Gladys T., author
John Wiley & Sons, 1960
Buku Teks
Hutchinson, 1959
Buku Referensi