@article{10_1017_S0017089500007163,
     author = {Wrobel, Volker},
     title = {Joint spectra and joint numerical ranges for pairwise commuting operators in {Banach} spaces},
     journal = {Glasgow mathematical journal},
     pages = {145--153},
     year = {1988},
     volume = {30},
     number = {2},
     doi = {10.1017/S0017089500007163},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500007163/}
}