A. MADDU, H. YULWAN, I. SOFIAN, A. S. SULAEMAN, and P. A. PUTRO, “Synthesis of CaCu3Ti4O12 utilizing eggshell waste as a calcium source: Structure, morphology, and dielectric properties”, J Met Mater Miner, vol. 32, no. 3, pp. 80–85, Sep. 2022.