@article{MS2_1963__13_165860,
     author = {E.R. Deal},
     title = {Quasi-Spectral {Theory.}},
     journal = {Mathematica Scandinavica},
     pages = {188--198},
     publisher = {mathdoc},
     volume = {13},
     year = {1963},
     zbl = {0146.12605},
     url = {http://geodesic.mathdoc.fr/item/MS2_1963__13_165860/}
}