@article{oai:aue.repo.nii.ac.jp:00007371,
 author = {Nozaki, Hiroshi},
 issue = {7},
 journal = {Discrete Mathematics},
 month = {Jul},
 note = {text, We deal with connected k-regular multigraphs of order n that has only three distinct eigenvalues. In this paper, we study the largest possible number of vertices of such a graph for given k. For k = 2; 3; 7, the Moore graphs are largest. For k ≠ 2; 3; 7; 57, we show an upper bound n ≤ k2 - k + 1, with equality if and only if there exists a  nite projective plane of order k - 1 that admits a polarity.},
 pages = {2134--2138},
 title = {Largest regular multigraphs with three distinct eigenvalues},
 volume = {342},
 year = {2019}
}