@article{RSMUP_1969__42__201_0, author = {Schaefer, D. J.}, title = {On multiplicity functions and {Lebesgue} area}, journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova}, pages = {201--207}, publisher = {Seminario Matematico of the University of Padua}, volume = {42}, year = {1969}, mrnumber = {276444}, zbl = {0234.28011}, language = {en}, url = {http://www.numdam.org/item/RSMUP_1969__42__201_0/} }