@article{CMH_1960__34_139182,
     author = {H.L. Royden},
     title = {On a {Class} of {Null-Bounded} {RIEMANN} {Surfaces.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {52--66},
     publisher = {mathdoc},
     volume = {34},
     year = {1960},
     zbl = {0113.05702},
     url = {http://geodesic.mathdoc.fr/item/CMH_1960__34_139182/}
}