@article{10_4153_CMB_1988_065_4,
     author = {Kalton, N. J.},
     title = {Sums of {Idempotents} in {Banach} {Algebras}},
     journal = {Canadian mathematical bulletin},
     pages = {448--451},
     year = {1988},
     volume = {31},
     number = {4},
     doi = {10.4153/CMB-1988-065-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1988-065-4/}
}