@article{PORMA_1977__36_1_115297,
     author = {Hsiang, Fu Cheng},
     title = {On the absolute convergence factors of an orthogonal series},
     journal = {Portugaliae mathematica},
     pages = {13--15},
     publisher = {mathdoc},
     volume = {36},
     number = {1},
     year = {1977},
     mrnumber = {0535218},
     zbl = {0407.42010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1977__36_1_115297/}
}