2) TODD D. K.: Groundwater Hydrology, 336 p. John Wiley Sons (1959)
3) 榧根勇: 水の循環, 水文学講座3, p.共立出版 (1973)
4) MOMIKURA Y., NAKAYAMA Y.: Groundwater in the Skirts of Aso Volcano, Guide Book for Kyushu & Kansai Tour, pp.21-43, International Association of Hydrogeologists (1971)