Supported by Natural Science Foundation of China (Grant Nos. 11161035, 10801091), Research Crants from Ningxia University (Grant No. (E)ndzr09-1) and Scientific Research Project in Xinjiang (Grant No. XJEDU2009S101)
Let k be an integer with k ≥ 2 and G a graph with order n 〉 4k. We prove that if the minimum degree sum of any two nonadjacent vertices is at least n + k, then G contains a vertex cover with exactly k components su...