Helcionelloida Peel, 1991

Selection of related publications
Isakar, M., Peel, J. S. 2007. Lower Cambriam helcionelloid molluscs from Estonia. GFF 129, 3, 255-262. DOI:10.1080/11035890701293255
Posti, E. 1978. New finds of platysolenitids and gastropods from the Lontova Stage of Estonia. Proceedings of the Academy of Sciences of the Estonian SSR. Geology 27, 3, 103-107.
Mens, K. A. & Pirrus, E. A. 1977. Stratotypes of the Cambrian Formations of Estonia.
Öpik, A. 1926. Über den estländischen Blauen Ton. Tartu Ülikooli juures oleva Loodusuurijate Seltsi Aruanded 33, 1, 39-47.