Dienta, D. G. R. D., Putri, F. E., & Riana, N. (2026). Strengthening Logical Thinking in Children Aged 5-6 Years Through BUMIKA Geometry: A Classroom Action Research Study. Transformasi : Jurnal Penelitian Dan Pengembangan Pendidikan Non Formal Informal, 12(2), 1010–1018. https://doi.org/10.33394/jtni.v12i2.19141