@article{700196,
     title = {A general method of majorating of Dirichlet problem solutions},
     booktitle = {Differential Equations and Their Applications},
     series = {GDML\_Books},
     publisher = {Slovensk\'e pedagogick\'e nakladate\v lstvo},
     address = {Bratislava},
     year = {1967},
     pages = {243-248},
     url = {http://dml.mathdoc.fr/item/700196}
}

Alexandrov, A. D. A general method of majorating of Dirichlet problem solutions, dans Differential Equations and Their Applications, GDML_Books,  (1967), pp. 243-248. http://gdmltest.u-ga.fr/item/700196/