%0 Journal Article %A Dressler, Robert E. %T A property of the $\varphi $ and $\sigma _j$ functions %J Compositio Mathematica %D 1975 %P 115-118 %V 31 %N 2 %I Noordhoff International Publishing %U http://www.numdam.org/item/CM_1975__31_2_115_0/ %G en %F CM_1975__31_2_115_0