Safiah, Intan, Muhammad Yunus, Amar Zaki, Ahadin, and Hasniyati. 2025. “Development of Ubiquitous Project-Based Learning (U-Pjbl) Model to Improve Critical Thinking Skills of Elementary School Students”. Journal of Learning for Development 12 (2):313-29. https://doi.org/10.56059/jl4d.v12i2.1358.