@article {IOPORT.50193415,
    author       = {Bilu, Yonatan and Linial, Nathan},
    title        = {Ramanujan signing of regular graphs},
    year         = {2004},
    journal      = {Combinatorics, Probability & Computing},
    volume       = {13},
    number       = {6},
    pages        = {911-912},
    doi          = {10.1017/S0963548304006509},
    identifier   = {50193415},
}