SABRY KH. MOHAMED; NAGLAA M. SHALABY. MICRODETERMINATION OF SILDENAFIL, TADALAFIL AND VARDENAFIL DRUGS EMPLOYED IN THE ERECTILE DYSFUNCTION THERAPY IN PHARMACEUTICAL FORMULATIONS AND URINE SAMPLES OF DIABETIC PATIENTS TYPE-II IN TAIF AREA, SAUDIA ARABIA USING ATOMIC EMISSION AND ATOMIC ABSORP. ijpbs 2013, 4, 1037-1046.