@article{PIM_1971_N_S_11_25_a20,
     author = {Drago\v{s} M. Cvetkovi\'c},
     title = {The {Spectral} {Method} {For} {Determining} {The} {Number} {Of} {Trees}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {135 },
     publisher = {mathdoc},
     volume = {_N_S_11},
     number = {25},
     year = {1971},
     url = {http://geodesic.mathdoc.fr/item/PIM_1971_N_S_11_25_a20/}
}