Alobeidani, Mohammed Juma Mohammed, and Sueraya Che Haron. 2022. “Degree of the Availability of the 21st Century Skills in the Social Studies Textbooks of the Twelfth Grade of Post-Basic Education in Sultanate of Oman”. Journal of Curriculum and Teaching Methodology 1 (8): 61-85. https://doi.org/10.26389/AJSRP.D200222.