@article{10_1017_S0017089500006352,
     author = {Ch\={o}, Muneo},
     title = {Joint spectra of operators on {Banach} space},
     journal = {Glasgow mathematical journal},
     pages = {69--72},
     year = {1986},
     volume = {28},
     number = {1},
     doi = {10.1017/S0017089500006352},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006352/}
}