Inversion of 1-D Resistivity Data using RR-PSO algorithm to identify Shallow Gas in BalikpapanDharma Arung-Laby, Abdi Suprayitno, Kukuh J Waskita and Mohammad LutfiBIO Web Conf., 73 (2023) 04006DOI: https://doi.org/10.1051/bioconf/20237304006