داڕێژە:Peel 1991

«Functional Morphology of the Class Helcionelloida Nov., and the Early Evolution of the Mollusca». The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press. 1991. pp. 157–177. ISBN 978-0-521-40242-2. {{cite book}}: |first= missing |last= (یارمەتی)