1. Anaorganisches Kristallwachstum bei lebenden Mollusken;Bandel;Paläontologische Zeitschrift,1975
2. Shell ultrastructures of some Maastrichtian Ammonoidea and Coleoidea and their taxonomic implications;Birkelund;Det Kongelige Danske Videnskabernes Selskab, Biologiske Skrifter,1974
3. Further remarks on the post-embryonic Hypophylloceras shell;Birkelund;Bulletin of the Geological Society of Denmark,1975
4. Mode and Rate of Growth in Ammonoids