Diethoxyphosphinylformic Acid Ethyl Ester, Triethyl Phosphonoformate, Ethyl DiethoxyphosphinylforMate, Ethyl diethoxyphospinylformate,Triethyl phosphonoformate, Foscarnet impurity D, Ethyl diethoxyphospinylformate, (Ethoxycarbonyl)phosphonic Acid Diethyl Ester, ethyl diethoxyphosphorylformate