Chitinozoan biostratigraphy of the Upper Ordovician D. clingani and P. linearis graptolite biozones on the Island of Bornholm, DenmarkVandenbroucke, Thijs R. A.; Recourt, Philippe; Nõlvak, Jaak; Nielsen, Arne T.Stratigraphy2013 / p. 281-301 : illhttps://biblio.ugent.be/publication/5645860