Sakapurnama, Eko, et al. “Strategy Formulation Roadmap Human Capital: Action Research Based Soft System Methodology, Case in PT Angkasa Pura I”. The Asian Journal of Technology Management (AJTM), vol. 13, no. 2, Aug. 2020, pp. 145-57, doi:10.12695/ajtm.2020.13.2.4.