@article{PIM_1981_N_S_29_43_a29,
     author = {Aleksandar Torga\v{s}ev},
     title = {On {Spectra} of {Infinite} {Graphs}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {269 },
     publisher = {mathdoc},
     volume = {_N_S_29},
     number = {43},
     year = {1981},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1981_N_S_29_43_a29/}
}