Malik, A. A.; Bakarman, M. A.; Butt, N. S. Construct Validity and Factor Structure of the Pittsburgh Sleep Quality Index (PSQI) Among Physicians in Jeddah, Kingdom of Saudi Arabia. Pak.j.stat.oper.res. 2018, 14 (4), 935-943. https://doi.org/10.18187/pjsor.v14i4.2729.