Pengaruh kegiatan pariwisata terhadap kualitas airtanah bebas di daerah Beting Gisik Pangandaran Jawa Barat=The Influence of Tourism Activity Towards the Quality of Unconfined Groundwater in the Beach Ridge Area of ... - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 1998)