1，
Articles
Land Use and Agricultural Productivity in Zimbabwe

Dan Weinera1, Sam Moyoa2, Barry Munslowa3 and Phil O'Keefea4

The Journal of Modern African Studies (1985), 23:251-285 Cambridge University Press
Copyright © Cambridge University Press 1985
doi:10.1017/S0022278X00000173
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=2159516


2。ENVIRONMENTAL QUALITY AND LAND PRODUCTIVITY: A COMPARISON OF THE AGRICULTURAL LAND BASE OF THE USSR AND NORTH AMERICA
N. C. FIELD
Canadian Geographer / Le Géographe canadien
Volume 12, Issue 1 , Pages1 - 14
1968 Canadian Association of Geographers

http://www3.interscience.wiley.com/journal/119866367/abstract?CRETRY=1&SRETRY=0