A systematic literature review of visual feature learning: deep learning techniques, applications, challenges and future directions. - Mohammed Abdullahi; Olaide Nathaniel Oyelade; Armand Florentin Donfack Kana; Mustapha Aminu Bagiwa; Fatimah Binta Abdullahi; Sahalu B. Junaidu; Ibrahim Iliyasu; Ajayi Ore-ofe; Haruna Chiroma (Multim. Tools Appl., 2025)