R. Eso, Muhammad Abdullah Azam Undu, Sumarno, and Muhammad Anas, “Efek Variasi Waktu dan Jumlah Lilitan pada Sistem Filter Elektromagnetik Terhadap Penurunan Kadar Pb, Zn dan Co: (Effects of Time Variation and Number of Turns in Electromagnetic Filter Systems on Decreasing Levels of Pb, Zn and Co)”, Gravitasi, vol. 19, no. 2, pp. 40-43, Dec. 2020.