y.al-Khafaf S, هلال. Digital Reference service: Its concept, styles, with a Proposal of its establishment at University of Mousl Central Library. RADAB [Internet]. 2025 Jun. 24 [cited 2025 Aug. 6];42(63):431-62. Available from: https://ojs.uomosul.edu.iq/index.php/radab/article/view/2927