@article{CRPHYS_2019__20_1-2_64_0,
     author = {Horst Bettin and Kenichi Fujii and Arnold Nicolaus},
     title = {Silicon spheres for the future realization of the kilogram and the mole},
     journal = {Comptes Rendus. Physique},
     pages = {64--76},
     publisher = {Elsevier},
     volume = {20},
     number = {1-2},
     year = {2019},
     doi = {10.1016/j.crhy.2018.12.005},
     language = {en},
}