@book{Kaufman1990,
author = {Kaufman, L. and Rousseeuw, P.J.},
title= {Finding groups in data: An introduction to cluster analysis},
year = {1990},
doi = {10.1002/9780470316801},
address = {Hoboken, NJ},
publisher = {Wiley},
series = {Wiley Series in Probability and Statistics},
}