@article{10_4064_cm101_2_6,
     author = {Victoria Knopova},
     title = {Semigroups generated by certain
 pseudo-differential operators on the half-space ${\Bbb R}_{0+}^{n+1}$},
     journal = {Colloquium Mathematicum},
     pages = {221--236},
     publisher = {mathdoc},
     volume = {101},
     number = {2},
     year = {2004},
     doi = {10.4064/cm101-2-6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm101-2-6/}
}