http://reply.papertrans.cn/2/106/10588/10588-11.png
http://reply.papertrans.cn/2/106/10588/10588-12.png
http://reply.papertrans.cn/2/106/10588/10588-13.png
http://reply.papertrans.cn/2/106/10588/10588-14.png
http://reply.papertrans.cn/2/106/10588/10588-15.png
http://reply.papertrans.cn/2/106/10588/10588-16.png
http://reply.papertrans.cn/2/106/10588/10588-17.png
http://reply.papertrans.cn/2/106/10588/10588-18.png
Submitted on: 18 July 1999.
Revised on: 10 August 1999.
Accepted on: 06 September 1999.
___________________GEOGRAPHICAL REVIEW---TAYLOR & FRANCIS INC
http://reply.papertrans.cn/2/106/10588/10588-20.png