TY  - BOOK
AU  - Durr, W.K.
AU  - William K. Durr; Vivian O. Windley and Mildred C. Yates
TI  - Keystone
SN  - 0395204135
AV  - DUCEPR6062.O86K4 
PY  - 1976///
CY  - Boston
PB  - Houghton mifflin
KW  - Social science
N1  - Includes glossary
ER  -