Z. K. Khali and R. Rosli, “Topic analysis of Algebraic Expressions and Algebraic Formulae in Form 1 and Form 2 Mathematics Textbooks: Analisis topik Ungkapan Algebra dan Rumus Algebra dalam Buku Teks Matematik Tingkatan 1 dan Tingkatan 2”, JPSMM, vol. 11, no. 2, pp. 26–38, Sep. 2021.