@article{10_4064_ap_34_1_39_42,
     author = {J. Zderkiewicz},
     title = {Sur le rayon de \ensuremath{\beta}-convexit\'e de la famille $\ensuremath{\Sigma}*_a$},
     journal = {Annales Polonici Mathematici},
     pages = {39--42},
     publisher = {mathdoc},
     volume = {34},
     number = {1},
     year = {1977},
     doi = {10.4064/ap-34-1-39-42},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-34-1-39-42/}
}