Scalidophora

Budd, Graham E. 2001: Why are Arthropods Segmented? Evolution and Development, vol. 3 (5): 332-342.
Palaeoscolecida, Priapozoa

Budd, G. E., and Jensen, S. 2000. A critical reappraisal of the fossil record of bilaterian phyla. Biol. Rev. 74: 253–295.
Palaeoscolecida, Priapozoa

Conway Morris, S. 1977. Fossil priapulid worms. Special Papers in Palaeontology 20: 1.95.
Priapozoa

Conway Morris, S. and Peel, J.S. 2010. New palaeoscolecidan worms from the Lower Cambrian: Sirius Passet, Latham Shale and Kinzers Shale. Acta Palaeontologica Polonica 55 (1): 141–156. pdf
Palaeoscolecida, Priapozoa

Danovaro R., Dell'Anno A., Pusceddu A., Gambi C., Heiner I. & Kristensen R. M. (2010). "The first metazoa living in permanently anoxic conditions". BMC Biology 8: 30. doi:10.1186/1741-7007-8-30.
Loricifera - overview

Dong XP, Donoghue PC, Cheng H, Liu JB, 2004, Fossil embryos from the Middle and Late Cambrian period of Hunan, south China. Nature 427(6971): 237-40. pdf
Scalidophora.

Dzik, J., and Krumbiegel, G. 1989. The oldest 'onychophoran' Xenusion: a link connecting phyla? Lethaia 22: 169–182. Palaeoscolecida, Priapozoa

Glaessner, Martin F. 1979. Lower Cambrian Crustacea and annelid worms from Kangaroo Island, South Australia. Alçheringa, 3: 21-31.
Palaeoscolex

Halanych, K. M. (2004). The new view of animal phylogeny. Annual Review of Ecology and Systematics. 35, 229-256.
Scalidophora.

Han, J., J. Liu, Z. Zhang, X. Zhang & D. Shu. 2007. Trunk ornament on the palaeoscolecid worms Cricocosmia and Tabelliscolex from the Early Cambrian Chengjiang deposits of China. Acta Palaeontologica Polonica 52 (2): 423-431.
Palaeoscolecida

Harvey, T., Dong, X. & Donoghue, C. 2010. Are palaeoscolecids ancestral ecdysozoans? Evolution and Development 12, 177-200. pdf
Palaeoscolecida, Scalidophora

Ivantsov, A. Y., & R. Wrona. 2004. Articulated palaeoscolecid sclerite arrays from the Lower Cambrian of eastern Siberia. Acta Geologica Polonica 54 (1): 1-22. pdf
Palaeoscolex, Palaeoscolecida

Maas, A., Waloszek, D., Haug, J.T. & Müller, K.J., 2009:12:24. Loricate larvae (Scalidophora) from the Middle Cambrian of Australia. Memoirs of the Association of Australasian Palaeontologists 37, 281-302. ISSN 0810-8889
pdf
Loricifera

Nielsen, C. (2001). Animal Evolution: Interrelationships of the Living Phyla, Second Edition. 563 pp. Oxford University Press.
Scalidophora.

Peel, J. S. (2010). "A Corset-Like Fossil from the Cambrian Sirius Passet Lagerstätte of North Greenland and Its Implications for Cycloneuralian Evolution". Journal of Paleontology 84 (2): 332–340. doi:10.1666/09-102R.1
Loricifera

Repetski, J. E. 1981. An Ordovician occurrence of Utahphospha Müller & Miller. Journal of Paleontology 55 (2): 395-400.
Palaeoscolecida

Sørensen, M. V., Hebsgaard M. B., Heiner I., Glenner H., Willerslev E., & Kristensen R. M. (2008). New data from an enigmatic phylum: evidence from molecular sequence data supports a sister-group relationship between Loricifera and Nematomorpha. Journal of Zoological Systematics and Evolutionary Research. 46, 231-239.
Scalidophora.

Andrey Yu. Zhuravlev, José Antonio Gámez Vintaned, and Eladio Liñán, 2011, The Palaeoscolecida and the evolution of the Ecdysozoa, From: Johnston, P.A., and Johnston K.J. (eds.), 2011. International Conference on the Cambrian Explosion, Proceedings. Palaeontographica Canadiana No. 31: 177–204. Joint Committee on Paleontological Monographs for CSPG/GAC pdf
Palaeoscolecida