A space lower bound for acceptance by one-way II2-alternating machines. - Viliam Geffert; Norbert Popély (RAIRO Theor. Informatics Appl., 2000)

Refinement of the Alternating Space Hierarchy. - Viliam Geffert; Norbert Popély (Comput. Artif. Intell., 2002)

The Communication Hierarchy of Time and Space Bounded Parallel Machines. - Norbert Popély (RAIRO Theor. Informatics Appl., 2003)