WILLEMS , C. J.; VONDRAK , A.; MUNSTERMAN , D. K.; DONSELAAR , M. E.; MIJNLIEFF , H. F. Regional geothermal aquifer architecture of the fluvial Lower Cretaceous Nieuwerkerk Formation – a palynological analysis. Netherlands Journal of Geosciences, v. 96, p. 319-330, 15 Jan. 2018.