@article{2009-J-IJCGA-EnclosingBallML,
author={Frank Nielsen and Richard Nock},
title={Approximating smallest enclosing balls with applications to machine learning},
journal={International Journal on Computational Geometry and Applications},
volume={19},
number={5},
pages={389-414
},
doi={10.1142/S0218195909003039},
year={2009}
}