Rianna, M.; Hussain, M. K.; Sembiring, T.; Guk-Guk, H. P. I. R.; Sitorus, K. J.; Setiadi, E. A.; Tetuko, . A. P. .; Sebayang, P. Micro-Magnetic Activity of the Fabricated MnFe2O4 via Co-Precipitation from Natural Iron Sand. sci. technol. indones. 2025, 10, 221-227.