The Santonian stage and substages - Lamolda, M; Hancock, J; Burnett, J; Collom, C; Christensen, W; Dhondt, A; Gardin, S; Gräfe, K; Ion, J; Kauffman, E; Kennedy, W; Kopaevich, L; et al. (Bulletin de l'Institut Royal des Sciences Naturelles de Belqique, Sciences de la Terre, 1996)