%0 Journal Article %A R.E. Barnhill %A J.A. Gregory %T Sard Kernel Theorems on Triangular Domains with Application to Finite Element Error Bounds. %J Numerische Mathematik %D 1975 %P 215-230 %V 25 %I mathdoc %U http://geodesic.mathdoc.fr/item/NUMA_1975__25_132375/ %F NUMA_1975__25_132375