TY  - BOOK
AU  - Durr, William K.
AU  - Windley, Vivian O.
AU  - Yates, Mildred C.
TI  - Keystone
SN  - 0395265940
U1  - 428.6 
PY  - 1979///
CY  - Boston
PB  - Houghton Mifflin Company
ER  -