@article{PIM_1992_N_S_51_65_a2,
     author = {Aleksandar Torga\v{s}ev},
     title = {On the {Numbers} of {Positive} and {Negative} {Eigenvalues} of a {Graph}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {25 },
     publisher = {mathdoc},
     volume = {_N_S_51},
     number = {65},
     year = {1992},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1992_N_S_51_65_a2/}
}