Kastner, M.; Asaro, F.; Michel, H. V.; Alvarez, Walter; Alvarez, Luis W. (1984): The precursor of the Cretaceous-Tertiary boundary clays at Stevns Klint, Denmark, and DSDP Hole 465A. American Association for the Advancement of Science, Washington, DC, United States, Science, 226 (4671), 137-143, georefid:1985-029574