TY  - SER
AU  -  Marsh, George P. 
TI  -  The Earth as Modified by Human Action 
AV  - GF 
PY  - 2004///
PB  -  Project Gutenberg, 
KW  -  Physical geography
KW  -  Conservation of natural resources
KW  -  Human geography
KW  -  Nature -- Effect of human beings on
N1  -  Public domain in the USA;  Text
UR  -  http://www.gutenberg.org/ebooks/6019
ER  -