@article{10_4064_sm148_1_1,
     author = {Mohamed Barraa and Mohamed Boumazgour},
     title = {Spectra of the difference, sum and product of idempotents},
     journal = {Studia Mathematica},
     pages = {1--3},
     publisher = {mathdoc},
     volume = {148},
     number = {1},
     year = {2001},
     doi = {10.4064/sm148-1-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm148-1-1/}
}