TY  - RPRT
TI  - From sundials to atomic clocks; understanding time and fluency 
AU  - Jespersen, James
AU  - Fitz-Randolph, Jane
PY  - 1977
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS MONO 155
DO  - 10.6028/NBS.MONO.155
ER  -