@article{fcds00,
   author = {T. Morzy and M. Wojciechowski and M. Zakrzewicz},
   title = {Clustering Sequences of Categorical Values},
   journal = {Foundations of Computing and Decision Sciences},
   publisher = {Publishing House of Poznan University of Technology},
   issn = "0867-6356"
   year = 2000,
   volume = 25,
   number = 3,
   pages = "175--191",
}