Langi, Evy Lalan, et al. “Construction of Integer Operations of the Gasing-Mathematics Method from the Perspective of APOS Theory”. QALAMUNA: Jurnal Pendidikan, Sosial, Dan Agama, vol. 17, no. 2, Dec. 2025, pp. 1551-66, doi:10.37680/qalamuna.v17i2.8110.