@article{10_4064_sm_44_6_583_595,
     author = {S. Kwapie\'n},
     title = {Isomorphic characterizations of inner product spaces by orthogonal series with vector valued coefficients},
     journal = {Studia Mathematica},
     pages = {583--595},
     publisher = {mathdoc},
     volume = {44},
     number = {6},
     year = {1972},
     doi = {10.4064/sm-44-6-583-595},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-44-6-583-595/}
}