Clark, Timothy R.
Cambridge University Press, 2011
eBooks
De Blij, Harm J.
John Wiley & Sons, 1993
Buku Teks
Penna, Anthony N
Blackwell, 2013
Buku Teks
De Blij, Harm J.
John Wiley & Sons, 1996
Buku Referensi
Adams, James E.
Wiley-Blackwell, 2009
Buku Teks