Wagner, R. H., Winkler Prins, C. F. y Riding, R. E. (1971) «Lithostratigraphic units of the lower part of the Carboniferous in northern León, Spain (with a “Note on some goniatite faunas” by C. H. WAGNER-GENTIS)», Trabajos de Geología, 4(4), pp. 603–665. doi: 10.17811/tdg.4.1971.603-665.