Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) YANG Heejun and SHIBATA Tomo,Long-term changes in unconfined groundwater level in the southern Beppu volcanic fan,Journal of Groundwater Hydrology,09134182,Japanese Association of Groundwater Hydrology,2021-08-31,63,3,151-157,https://cir.nii.ac.jp/crid/1390289475882170752,https://doi.org/10.5917/jagh.63.151