TY  - BOOK
AU  - Trigger Bruce G
TI  - Sociocultural evolution:  Calculation and contingency   
T2  - New Perspectives on the Past
SN  - 1557869774
U1  - Y:6, N8 
PY  - 1998///
CY  - Oxford
PB  - Blackwell Publishers         
KW  - Social Change
N1  - Bibliography: P 267-93
ER  -