Haas, Ernst B.
Standford University Press, 1970
Buku Teks
Akaruese, Lucky, author
Xlibris Corporation, 2012
Buku Teks
North-South Institute , 1993
Buku Teks
Chavarro, Jimena Murillo, author
Intersentia , 2015
eBooks
Pennacchia, Michael A., author
Xlibris Corporation, 2012
Buku Teks