Crawford, R.M.
Hutchinson's University Library, 1955
Buku Teks
Crawford, R.M.
Hutchinson University Library, 1952.
Buku Teks
Berney, Maurice
Angus and Robertson, 1965
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 1994
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 1997
Buku Teks