A combination of trie-trees and inverted files for the indexing of set-valued attributes. - Manolis Terrovitis; Spyros Passas; Panos Vassiliadis; Timos K. Sellis (CIKM, 2006)

Defining a Taxonomy for Research Areas on ICT for Governance and Policy Modelling. - Fenareti Lampathaki; Yannis Charalabidis; Spyros Passas; David Osimo; Melanie Bicking; Maria A. Wimmer; Dimitris Askounis (EGOV, 2010)