Pyramidal model on civil information system. - Hristo Toudjarov; Stefan Kalchev; Galya Nenova (CompSysTech, 2000)

Municipal information system. - Hristo Toudjarov; Stefan Kalchev; Galya Nenova (CompSysTech, 2000)

Type decisions for development of information systems from users. - Galya Nenova (CompSysTech, 2003)