M. K. Jacob, T. K. Pal, V. Sunil Kumar, L. J. Archana, and R. K. Sreelatha, “Macro Invertebrate Fossil Fauna (Mollusca) from Quilon Limestone Formation, Kerala State: Characteristics and Stratigraphic Implications”, rzsi, vol. 112, no. 4, pp. 19–29, Dec. 2012.