Peel, J.S. “Functional Morphology, Evolution and Systematics of Early Palaeozoic Univalved Molluscs”. Bulletin Grønlands Geologiske Undersøgelse 161 (January 1, 1991): 1–116. Accessed May 19, 2024. https://geusjournals.org/index.php/bullggu/article/view/6717.