SYNTHESIS, CRYSTAL AND MOLECULAR STRUCTURE OF CATENA-(BIS(Μ1-OXALIC ACID)-Μ3-HYDROGEN OXALATE-DI-AQUA-SODIUM(I)) Article Kovalchukova Olga, Aldoshin Sergey, Utenyshev Andrey, Bogenko Konstantin, Tkachev Valeriy Communications in Inorganic Synthesis. University of Santiago of Chile. Vol. 3. 2015. P. 23-25