@article{MV_1972_24_1_a21,
     author = {D. M. Cvetkovi\'c and I. M. Gutman},
     title = {The algebraic multiplicity of the number zero in the spectrum of a bipartite graph},
     journal = {Matemati\v{c}ki vesnik},
     pages = {141 },
     publisher = {mathdoc},
     volume = {24},
     number = {1},
     year = {1972},
     url = {http://geodesic.mathdoc.fr/item/MV_1972_24_1_a21/}
}