M. D. Nasution, M. R. Syahputra, and I. H. Rambe, “MODELLING AND NUMERICAL ANALYSIS FOR CRACK PROPAGATION IN COMBINING CONCRETE WITH 25% FEATHER SHELL POWDER USING FINITE ELEMENT METHOD”, BAREKENG: J. Math. & App., vol. 19, no. 4, pp. 2419-2430, Sep. 2025.