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Halkieriids from the Lower Cambrian of North Greenland and their Role in Early Protostome Evolution". Philosophical Transactions of the Royal Society B 347 (1321):
(1995-03-17). “Evidence from 18S ribosomal DNA that the lophophorates are protostome animals” (英語). Science 267 (5204): 1641–1643. doi:10.1126/science.7886451