%0 Journal Article %A Robert Butts %A Pasquale Porcelli %T Multiplicity theory %J Studia Mathematica %D 1970 %P 391-405 %V 38 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-38-1-391-405/ %R 10.4064/sm-38-1-391-405 %G en %F 10_4064_sm_38_1_391_405