TY  - BOOK
AU  - Burnham,P.C..
AU  - Ellen,R.F..
TI  - Social and ecologi systems / 
U1  - 301.31 
PY  - 1979///
CY  - London : 
PB  - Academic Press , 
KW  - MAN-INFLUENCE OF ENVIRONMENT
N1  - includes index
ER  -