S. J. de Jong and W. Geirnaert (1979) “The groundwater thermal regime in the Flevo polders and Gelderse Vallei (Southern IJsselmeer area, the Netherlands)”, Netherlands Journal of Geosciences, pp. 295-304. Available at: https://njgjournal.nl/index.php/njg/article/view/13959 (Accessed: 5April2026).