@article{TIMB_2015_23_2_a10,
     author = {A. A. Makhnev},
     title = {Strongly regular graphs with nonprincipal eigenvalue 4 and its extensions},
     journal = {Trudy Instituta matematiki},
     pages = {82--87},
     publisher = {mathdoc},
     volume = {23},
     number = {2},
     year = {2015},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMB_2015_23_2_a10/}
}