Purwanto, M. S., Susilo, A., Naba, A., Bahri, A. S. and Navisa, S. (2025) “Integration of Principal Component Analysis and Very Low Frequency Geophysical Method for Modeling Recharge Area Distribution: The Case Study of Krawak Spring, Tuban”, Engineering, Technology & Applied Science Research. Greece, 15(3), pp. 22644–22662. doi: 10.48084/etasr.10508.