@article{10_4064_cm87_1_1,
     author = {Michael D. O'Neill},
     title = {Vertical variation of harmonic functions
in upper half-spaces},
     journal = {Colloquium Mathematicum},
     pages = {1--12},
     publisher = {mathdoc},
     volume = {87},
     number = {1},
     year = {2001},
     doi = {10.4064/cm87-1-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm87-1-1/}
}