TY  - BOOK
AU  - Tannenbaum,Beulah
TI  - Understanding time: the science of clocks and calendars 
PY  - 1958///
CY  - New York
PB  - McGraw-Hill
KW  - Time
KW  - Clocks and watches
KW  - Chronology
N1  - Includes index
ER  -