Kobayashi, Y. , Shirochi, T. , Yasuda, Y. , Morita, T.. "Preparation of Metallic Copper Nanoparticles by Reduction of Copper Ions in Aqueous Solution and Their Metal-Metal Bonding Properties". World Academy of Science, Engineering and Technology, Open Science Index 82, International Journal of Materials and Metallurgical Engineering, (2013), 7(10), 769 - 772.