@PHDTHESIS{AKPHD2013,
    title = {Knowledge extraction methods for document collections},
	author = {Argyris Kalogeratos},
	school = {University of Ioannina, Dept. Computer Science},
	booktitle = {PhD Thesis},
	supervisor = {Aristidis Likas},
	year = {2013},	@url={http://195.130.121.171/akaloger/files/2011/02/PhD_Thesis_A.Kalogeratos_2013.pdf\# page=113}
}