@misc{1203171, author = {Eyvon M Petty}, title = {NIST time and frequency bulletin, no. 609:}, year = {2008}, month = {2008-01-01 05:01:00}, publisher = {, National Institute of Standards and Technology, Gaithersburg, MD}, doi = {https://doi.org/10.6028/NIST.IR.6653-09}, language = {en}, }