@article{CRPHYS_2019__20_1-2_153_0,
     author = {S\'ebastien Bize},
     title = {The unit of time: {Present} and future directions},
     journal = {Comptes Rendus. Physique},
     pages = {153--168},
     publisher = {Elsevier},
     volume = {20},
     number = {1-2},
     year = {2019},
     doi = {10.1016/j.crhy.2019.02.002},
     language = {en},
}