Doguzhaeva, Mapes & Mutvei 1999. A Late Carboniferous spirulid coleoid from the southern mid-continent (USA). Shell wall ultrastructure and evolutionary implications. Advancing research on living and fossil cephalopods: development and evolution: form, construction, and function: taphonomy, palaeoecology, palaeobiogeography, biostratigraphy, and basin analysis., Kluwer Academic/Plenum Publishers, New York, Boston etc., 1999: i-xvi, 1-550. Chapter pagination: 47-57