@article{MOMA_1963__67_177222,
     author = {Marston Morse},
     title = {Harmonic {Extensions.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {317--325},
     publisher = {mathdoc},
     volume = {67},
     year = {1963},
     zbl = {0151.16004},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1963__67_177222/}
}