H.W. Haak (1994) “Seismotectonics and seismic hazard in the Roer Valley Graben; with emphasis on the Roermond earthquake of April 13, 1992: Workshop recommendations”, Netherlands Journal of Geosciences, 73, pp. 93-94. Available at: https://njgjournal.nl/index.php/njg/article/view/12453 (Accessed: 7April2026).