Authors Year Title
Kullmann, Wagner & Winkler_Prins 2007 Significance for international correlation of the Perapertú Formation in Northern Palencia, Cantabrian Mountains. Tectonic/stratigraphic context and description of Mississippian and Upper Bashkirian Goniatites.
Revista Española de Paleontología, 22 (2), 127-145, 8 fig.,  Madrid.