M. Zahra, D. M. H. Kee, S. S. Teh, and G. D. Paul, “Psychological Capital Impact on Extra Role Behaviour via Work Engagement: Evidence from the Pakistani Banking Sector”, IJBF, vol. 17, no. 1, pp. 27 – 52, Dec. 2021, doi: 10.32890/ijbf2022.17.1.2.