@article{10_4153_CJM_1972_059_8,
     author = {Ruckle, William H.},
     title = {The {Extent} of the {Sequence} {Space} {Associated} with a {Basis}},
     journal = {Canadian journal of mathematics},
     pages = {636--641},
     year = {1972},
     volume = {24},
     number = {4},
     doi = {10.4153/CJM-1972-059-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1972-059-8/}
}