Qi, Z., A. Younis, D. Chu, and S. Li. “A Facile and Template-Free One-Pot Synthesis of Mn3O4 Nanostructures As Electrochemical Supercapacitors”. Nano-Micro Letters, vol. 8, no. 2, Nov. 2015, pp. 165-73, doi:10.1007/s40820-015-0074-0.