Emerald Publishing, 2019
eBooks
John Sikula, senior editor ; Thomas Buttery, editor, Edith Guyton, editor
Macmillan Library Reference USA, 1996
Buku Referensi
Dobson, K.
Macmillan, 1975
Buku Teks SO
Justin Dillon, Meg Maguire, editor
McGraw-Hill, 2011
Buku Teks
Academic Press, 1968
Buku Teks