@article{MS2_1957__5_165663,
     author = {AUREL WINTNER},
     title = {The theorem of {Enestr\"om} and the extremal functions of {Landau-Schur}},
     journal = {Mathematica Scandinavica},
     pages = {236--240},
     publisher = {mathdoc},
     volume = {5},
     year = {1957},
     zbl = {0081.07103},
     url = {http://geodesic.mathdoc.fr/item/MS2_1957__5_165663/}
}