@incollection{AST_1980__80__53_0,
     author = {Willmore, T. J.},
     title = {An extension of {Pizzetti's} formula to riemmanian manifolds},
     booktitle = {Analyse sur les vari\'et\'es (Metz, 1979)},
     series = {Ast\'erisque},
     pages = {53--56},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {80},
     year = {1980},
     mrnumber = {620169},
     zbl = {0495.53041},
     language = {en},
     url = {http://www.numdam.org/item/AST_1980__80__53_0/}
}