@book{hartigan75,
  author = {Hartigan, J.},
  interhash = {fb9537d9624e0e10d39d92208e77de8c},
  intrahash = {1e578b491641715a807d1b6b136d2204},
  publisher = {John Wiley and Sons, New York},
  title = {Clustering Algorithms},
  year = 1975
}