@article{MAN_1971__193_182718,
     author = {Ivan SINGER},
     title = {On {Biorthogonal} {Systems} and {Total} {Sequences} of {Functionals.}},
     journal = {Mathematische Annalen},
     pages = {183--188},
     publisher = {mathdoc},
     volume = {193},
     year = {1971},
     zbl = {0207.43004},
     url = {http://geodesic.mathdoc.fr/item/MAN_1971__193_182718/}
}