@article{RLINA_1965_8_39_3-4_a6,
     author = {Carroll, Robert},
     title = {Some differential problems related to spectral theory in several operators},
     journal = {Atti della Accademia nazionale dei Lincei. Rendiconti della Classe di scienze fisiche, matematiche e naturali},
     pages = {170--174},
     publisher = {mathdoc},
     volume = {Ser. 8, 39},
     number = {3-4},
     year = {1965},
     zbl = {0148.38604},
     mrnumber = {0194937},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RLINA_1965_8_39_3-4_a6/}
}