@article{MAN_1940__117_160038,
     author = {R.M. Morris},
     title = {The internal problems of two dimensional potential theory},
     journal = {Mathematische Annalen},
     pages = {31--38},
     publisher = {mathdoc},
     volume = {117},
     year = {1940},
     zbl = {65.0422.02},
     url = {http://geodesic.mathdoc.fr/item/MAN_1940__117_160038/}
}