Durand, M., F. Fluteau, S. Bourquin, J. Broutin, and J.B. Díez. “The Permian-Triassic boundary and Early Triassic sedimentation in Western European basins: an overview”. Journal of Iberian Geology, vol. 33, vol. 33, no. 2, 2007, pp. 221-36, https://revistas.ucm.es/index.php/JIGE/article/view/JIGE0707210221A.