A. . AUSAVASUKHI, T. . SIRIPHALA, W. . LIMPHIRAT, and S. . NILMOUNG, “Leonardite humic acid activated carbon/MnO\(_{2}\) composite nanostructures for supercapacitors”, J Met Mater Miner, vol. 34, no. 2, p. 1932, Jun. 2024.