@article{oai:ynu.repo.nii.ac.jp:00006951,
 author = {Siran, Jozef},
 issue = {Special},
 journal = {Yokohama Mathematical Journal = 横濱市立大學紀要. D部門, 数学},
 month = {},
 note = {application/pdf, Regular coverings of graphs have been treated in the literature in various ways . In this paper we develop an elementary theory of regular lifts of graphs and automorphisms by means of walks and their voltages, building thus up certain type of "walk calculus" associated with regular coverings.},
 pages = {113--128},
 title = {THE "WALK CALCULUS'' OF REGULAR LIFTS OF GRAPH AND MAP AUTOMORPHISMS},
 volume = {47},
 year = {1999}
}