@article{EXMATH_2001_2001_1_a24,
     author = {Ech-Cherif El Kettani, Mustapha and El Bouchibti, El Houcine},
     title = {Sobre las transformaciones aditivas que conservan el espectro puntual.},
     journal = {Extracta mathematicae},
     pages = {343-349},
     publisher = {mathdoc},
     volume = {16},
     number = {3},
     year = {2001},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_2001_2001_1_a24/}
}