@article{10_4064_sm147_2_5,
     author = {Lucien Chevalier and Alain Dufresnoy},
     title = {Sur les changements de signe
d'une fonction harmonique dans le demi-plan},
     journal = {Studia Mathematica},
     pages = {169--182},
     year = {2001},
     volume = {147},
     number = {2},
     doi = {10.4064/sm147-2-5},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm147-2-5/}
}