Subagtio, M.E., Nasution, N. and Jacky, M. 2021. The Effect of Problem-Based Learning and Discovery Learning on Students’ Critical and Creative Thinking Skills on Material of Islamic Kingdom Development. The Indonesian Journal of Social Studies. 4, 1 (Jul. 2021), 67–78. DOI:https://doi.org/10.26740/ijss.v4n1.p%p.