Lizah, R. et al. 2021. Development Of Teaching Materials In Mathematics Lessons In Semester Ii In Class IV Students Of Elementary School. Journal Universitas Muhammadiyah Gresik Engineering, Social Science, and Health International Conference (UMGESHIC). 1, 2 (Dec. 2021), 233–238. DOI:https://doi.org/10.30587/umgeshic.v1i2.3385.