Partridge, Eric, 1894-1979, author
Secker and Warburg, 1950
Buku Referensi
Schmadel, Lutz D., author
Springer, 2012
eBooks
compiled by E.G. Withycombe
Clarendom Press, 1950
Buku Referensi
Pence, Gregory E., author
McGraw-Hill, 2000
Buku Teks
Heaton, J.B., author
Longman, 1987
Buku Referensi