Detection of Sinkhole Potential Using Very Low Frequency (VLF) Method: A Case Study in Kedungsalam Village, Malang RegencyRahmat Faizal, Adi Susilo, Alamsyah M. Juwono, Emma Yuliani, Muwardi Sutasoma, Muhardi, Mohammad Habibiy Idmi and Muhammad Fathur Rouf HasanE3S Web Conf., 652 (2025) 04002DOI: https://doi.org/10.1051/e3sconf/202565204002