@article{ASNSP_1973_3_27_3_491_0,
     author = {Al Bassam, M. A.},
     title = {Some operational properties of the {H-R} operator},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {491--506},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 27},
     number = {3},
     year = {1973},
     zbl = {0282.26006},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1973_3_27_3_491_0/}
}