Crawford, R.M.
Hutchinson's University Library, 1955
Buku Teks
Crawford, R.M.
Hutchinson University Library, 1952.
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 2005
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 1971
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 1981
Buku Teks