%0 Journal Article %A Takens, Floris %T The Lusternik-Schnirelman categories of a product space %J Compositio Mathematica %D 1970 %P 175-180 %V 22 %N 2 %I Wolters-Noordhoff Publishing %U http://archive.numdam.org/item/CM_1970__22_2_175_0/ %G en %F CM_1970__22_2_175_0