@article{ASNSP_1964_3_18_2_233_0,
     author = {S\'anchez, David A.},
     title = {Calculus of variations for integrals depending on a convolution product},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {233--254},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 18},
     number = {2},
     year = {1964},
     mrnumber = {169101},
     zbl = {0123.08101},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1964_3_18_2_233_0/}
}