@misc{1200256, author = {Kelsey Rodriguez}, title = {NIST time and frequency bulletin::December 2019}, year = {2019}, month = {2019-12-01 05:12:00}, publisher = {, National Institute of Standards and Technology, Gaithersburg, MD}, doi = {https://doi.org/10.6028/NIST.IR.8261-12}, language = {en}, }