@article{PIM_1978_N_S_23_37_a25,
     author = {Aleksandar Torga\v{s}ev},
     title = {Concept {Of} {The} {Spectral} {Sets} {In} {Wachs} {Spaces} {I} {(Definitions} {And} {Basic} {Properties)}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {213 },
     publisher = {mathdoc},
     volume = {_N_S_23},
     number = {37},
     year = {1978},
     url = {http://geodesic.mathdoc.fr/item/PIM_1978_N_S_23_37_a25/}
}