Madan, Manuj, and Alok Sahai. 2019. “Introduction of Environment Management Knowledge Area in PMBOK (Project Management Body of Knowledge): A Preliminary Study”. Balkans Journal of Emerging Trends in Social Sciences 2 (2). Belgrade, Serbia:124-33. https://doi.org/10.31410/Balkans.JETSS.2019.2.2.124-133.