Contact graph routing in DTN space networks: overview, enhancements and performance. - Giuseppe Araniti; Nikolaos Bezirgiannidis; Edward J. Birrane; Igor Bisio; Scott C. Burleigh; Carlo Caini; Marius Feldmann; Mario Marchese; John Segui; Kiyohisa Suzuki (IEEE Commun. Mag., 2015)