Covering space theory for directed topology. Goubault, Eric, Haucourt, Emmanuel, Krishnan, Sanjeevi (2009) Theory and Applications of Categories [electronic only]
Cryptographycal protocols in the Egerfood Information System. Liptai, Kálmán, Kusper, Gábor, Radványi, Tibor (2007) Annales Mathematicae et Informaticae