Citalopram R-Isomer

(R)-Citalopram Oxalate; Escitalopram - Impurity K (Oxalate Salt) (EP/BP); (R)-1-(3-(Dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile Oxalate; (R)-1-[3-(Dimethylamino)propyl]-1-(p-fluorophenyl)-5-phthalancarbonitrile oxalate (USP);