@incollection{JEDP_2004____A3_0,
     author = {Bony, Jean-Michel},
     title = {D\'ecomposition des fonctions positives en sommes de carr\'es},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {3},
     pages = {1--8},
     publisher = {Groupement de recherche 2434 du CNRS},
     year = {2004},
     doi = {10.5802/jedp.3},
     mrnumber = {2135358},
     language = {fr},
     url = {http://www.numdam.org/articles/10.5802/jedp.3/}
}