Lane, Edward William, author
Frederick Ungar Publishing, 1956
Buku Referensi
Axtell, Roger E.
John Wiley & Sons, 1995
Buku Teks
Laird, Charlton Grant, 1901-, author
Simon and Schuster, 1985
Buku Referensi
Lockhart, L.W.
Pustaka Rakjat, 1953
Buku Teks
Walter, Catherine
Cambridge University Press, 1992
Buku Teks