David Sislák Michal Pechoucek Martin Rehák Jan Tozicka Petr Benda Solving inaccessibility in multi-agent systems by mobile middle-agents. 73-87 2005 1 Multiagent and Grid Systems 2 http://iospress.metapress.com/content/cd40wbddkcga3197/ db/journals/mags/mags1.html#SislakPRTB05