“DIAGNOSTIC ACCURACY OF PROSTATE-SPECIFIC ANTIGEN DENSITY, FREE-TO-TOTAL PSA RATIO, AND DIGITAL RECTAL EXAMINATION IN DETECTING PROSTATE CANCER AMONG MEN WITH SERUM PSA LEVELS IN THE GRAY ZONE (4–10 NG/ML): A PROSPECTIVE OBSERVATIONAL STUDY” (2026) Frontier in Medical and Health Research, 4(3), pp. 2473–2482. Available at: https://fmhr.net/index.php/fmhr/article/view/3452 (Accessed: 8 November 2026).