@article{MAN_1972__198_162295,
     author = {J\"urgen Bliedtner and Klaus Janssen},
     title = {Harnacksche {Kegel} und {Metrik} in harmonischen {R\"aumen.}},
     journal = {Mathematische Annalen},
     pages = {85--98},
     publisher = {mathdoc},
     volume = {198},
     year = {1972},
     zbl = {0227.31010},
     url = {http://geodesic.mathdoc.fr/item/MAN_1972__198_162295/}
}