@article{Ssets,
    author  = {P. Fr\"anti and O. Virmajoki},
    title   = {Iterative shrinking method for clustering problems},
    journal = {Pattern Recognition},
    year    = {2006},
    volume  = {39},
    number  = {5},
    pages   = {761--765},
    doi     = {10.1016/j.patcog.2005.09.012},
    url     = {http://dx.doi.org/10.1016/j.patcog.2005.09.012}
}