TY  - BOOK
AU  - Heckenbach,Alan J.
AU  - Kegley,J.Colby
TI  - Elementary functions: : an approach to precaculus mathematics / 
U1  - 515.25 HEC 
PY  - 1970///
CY  - London : 
PB  - Collier-Macmillan, 
KW  - Functional equations
N1  -  Includes  index
ER  -