Gintautas Dzemyda Leonidas Sakalauskas Optimization and Knowledge-Based Technologies. 165-172 2009 20 Informatica, Lith. Acad. Sci. 2 http://iospress.metapress.com/content/678756751567h13v/ db/journals/informaticaLT/informaticaLT20.html#DzemydaS09