HASAN, Awadh Ahmed. Trends of criticism between the two caliphs: Omar bin Alkhatab and Abdulmalek bin Marwan: A comparative study of environment effect. Arab Journal for Sciences and Research Publishing, New Mexico, United States, v. 7, n. 1, p. 1–17, 2021. DOI: 10.26389/AJSRP.A101020. Disponível em: https://www.ajsrp.ojsexpert.com/index.php/ajsrp/article/view/3407. Acesso em: 20 dec. 2025.