J. Kullmann, R. H. Wagner, y C. F. Winkler Prins, «SIGNIFICANCE FOR INTERNATIONAL CORRELATION OF THE PERAPERTÚ FORMATION IN NORTHERN PALENCIA, CANTABRIAN MOUNTAINS. TECTONIC/STRATIGRAPHIC CONTEXT AND DESCRIPTION OF MISSISSIPPIAN AND UPPER BASHKIRIAN GONIATITES», Spanish J. Palaeontol., vol. 22, n.º 2, pp. 127–145, feb. 2021.