Mihai Badoiu, Kenneth L. Clarkson. Optimal core-sets for balls. Comput. Geom., 40(1):14-22, 2008. [doi]
@article{BadoiuC08,
title = {Optimal core-sets for balls},
author = {Mihai Badoiu and Kenneth L. Clarkson},
year = {2008},
doi = {10.1016/j.comgeo.2007.04.002},
url = {http://dx.doi.org/10.1016/j.comgeo.2007.04.002},
researchr = {https://researchr.org/publication/BadoiuC08},
cites = {0},
citedby = {0},
journal = {Comput. Geom.},
volume = {40},
number = {1},
pages = {14-22},
}