@article{ASNSP_1970_3_24_1_53_0,
     author = {Ceder, Jack G.},
     title = {Cluster directions of euclidean sets},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {53--63},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 24},
     number = {1},
     year = {1970},
     mrnumber = {260939},
     zbl = {0191.06001},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1970_3_24_1_53_0/}
}