Yahya Ould Hamidoune Anna S. Lladó Oriol Serra Ralph Tindell On Isoperimetric Connectivity in Vertex-Transitive Graphs. 139-144 2000 13 SIAM J. Discrete Math. 1 http://epubs.siam.org/sam-bin/dbq/article/30635 db/journals/siamdm/siamdm13.html#HamidouneLST00