[Canberra] Angus & Robertson 1989,
Buku Referensi
Daniel, Hawthorne
G.P. Putnam's Sons , 1943
Buku Teks
Oliver, Douglas L.
Harvard University Press, 1951
Buku Teks
Oliver, Douglas L.
Harvard University Press, 1958.
Buku Teks
Campbell, I.C.
University of Queensland Press, 1989
Buku Teks