L. M.  Ferrero-Vicente, Marco-Méndez, C., Loya-Fernández, Á., and Sánchez-Lizaso, J. L., ?Limiting factors on the distribution of shell/tube-dwelling sipunculans?, Journal of Experimental Marine Biology and Ecology, vol. 446, pp. 345-354, 2013.

M. E.  Rice, Piraino, J., and Reichardt, H. F., ?A survey of the Sipuncula of the Indian River Lagoon?, Bulletin of Marine Science, vol. 57, pp. 128-135, 1995.

E. B.  Cutler, The Sipuncula. Their systematics, biology and evolution. Ithaca, N.Y.: Cornell University Press, 1994, p. 453 pp.

B. P.  Haldar, ?Sipunculans of the Indian coast?, Memoirs of the Zoological Survey of India, vol. 17, pp. 1-169, 1991.

E. B.  Cutler and Cutler, N. J., ?A revision of the genus Aspidosiphon (Sipuncula)?, Proceedings of the Biological Society of Washington, vol. 102, pp. 826-865, 1989.

E. B.  Cutler and Cutler, N. J., ?A revision of the genus Aspidosiphon (Sipuncula, Aspidosiphonidae)?, Proceedings of the Biological Society of Washington, vol. 102, pp. 826-865, 1989.

A. E.  Migotto and Ditadi, A. S. F., ?Aspidosiphonidae (Sipuncula) from the northern and northeastern coast of Brazil?, Revista Brasileira de Biologia, vol. 48, pp. 245-263, 1988.

J. I. Saiz Salinas, Los tipos de Sipunculidos de de Quatrefages del Museo de Paris. Bilbao: Universidad del Pais Vasco, 1984.

E. B.  Cutler, ?A new species of Aspidosiphon (Sipuncula) from the western Atlantic Ocean?, Proceedings of the Biological Society of Washington, vol. 94, pp. 445-449, 1981.

E. B.  Cutler and Cutler, N. J., ?Sipuncula from Southern Brazil?, Boletim do Institut Oceanografico, Sao Paulo, vol. 29, pp. 1-8, 1980.

M. E.  Rice and MacIntyre, I. G., ?Distribution of Sipuncula in the coral reef community, Carrie Bow Cay, Belize?, Smithsonian Contributions to Marine Sciences, vol. 12, pp. 311-320, 1979.

E. B.  Cutler and Cutler, N. J., ?Madagascar and Indian Ocean Sipuncula?, Bulletin du Museum National d?Histoire Naturelle, Paris, vol. 4e, pp. 941-990, 1979.

C. M.  Yonge, ?A note on mutualism between sipunculans and Scleractinian corals?, International Symposium of Sipuncula and Echiura, vol. 1. Naucno Delo Press, Belgrade, pp. 305-311, 1975.

M. E.  Rice, ?Observations on the development of six species of Caribbean Sipuncula with a review of development in the phylum?, in Proceedings of the International Symposium of Sipuncula and Echiura, M. E.  Rice and Todorovic, M., Eds. Belgrade: Naucno Delo Press, 1975, pp. 141-160.

S. J.  Edmonds, ?A new species of Sipuncula (Aspidosiphon exiguus) belonging to the interstitial fauna of marine beaches collected by Mr. Botosaneanu during the second Cuban-Romanian Biospeleological Expedition to Cuba 1973?, International Journal of Speleology, vol. 6, pp. 187-192, 1974.

E. B.  Cutler, ?Sipuncula of the western North Atlantic?, Bulletin of the American Museum of Natural History, vol. 152, pp. 105-204, 1973.

A. C.  Stephen and Edmonds, S. J., The phyla Sipuncula and Echiura. London: Trustees British Mus. (Nat. Hist.), 1972, p. 528 pp.

M. E.  Rice and MacIntyre, I. G., ?A preliminary study of sipunculan burrows in rock thin sections?, Caribbean Journal of Science, vol. 12, pp. 41-44, 1972.

M. E.  Rice and Stephen, A. C., ?The type specimens of Sipuncula and Echiura described by J.E. Gray and W. Baird in the collections of the British Museum of Natural History?, Bulletin of the British Museum of Natural History, vol. 20, pp. 49-72, 1970.

E. B.  Cutler, ?New species of Sipuncula from the western North Atlantic?, Proceedings of the Biological Society of Washington, vol. 82, pp. 209-218, 1969.

V. V.  Murina, ?New species of Sipuncula from the Red Sea?, Zoologicheskii Zhurnal, vol. 47, pp. 1722-1725, 1968.

V. V.  Murina, ?On the sipunculid fauna of the littoral of Cuba?, Zoologicheskii Zhurnal, vol. 46, pp. 35-47, 1967.

E.  Wesenberg-Lund, ?Gephyrea?, Bulletin Musee royal d?Histoire naturelle de Belgique, vol. 13, pp. 1-23, 1937.

E.  Wesenberg-Lund, ?Gephyrea?, Zoology of Iceland, vol. 2, pp. 1-16, 1937.

A.  tenBroeke, ?Sipunculoidea und Echiuroidea?, Tierwelt Deutschlands und der Angrenzenden, vol. 15, pp. 156-168, 1929.

W.  Fischer, ?Sipunculoidea und Echiuroidea?, in Die Fauna Sudwest-Australiens, W.  Michaelsen and Hartmeyer, R., Eds. 1927, pp. 199-216.

R. V.  Chamberlin, ?Gephyrea?, Report of the Canadian Arctic Expedition 1913-18, vol. 9, pp. 3-7, 1920.

R.  Southern, ?Gephyrea of the coasts of Ireland?, Scientific Investigations of the Fisheries Branch, Department of Agriculture for Ireland, vol. 3, pp. 1-46, 1913.

J. H.  Gerould, ?The sipunculids of the eastern coast of North America?, Proceedings of the United States National Museum, vol. 44, pp. 373-437, 1913.

I.  Ikeda, ?The Gephyrea of Japan?, Journal of the College of Science, Imperial University of Tokyo, vol. 20, pp. 1-87, 1904.

C. P.  Sluiter, ?Beitrage zu der kenntnis der Gephyreen aus dem Malayischen Archipel?, Natuurkundig Tijdschrift voor Nederlandisch-Indie, vol. 45, pp. 472-517, 1886.

W. B.  Baird, ?Monograph on the species of worms belonging to the subclass Gephyreae?, Proceedings of the Zoological Society of London, vol. 1868, pp. 77-114, 1868.

K. M.  Diesing, ?Revision der Rhyngodeen?, Sitzungsberichte de mathematisch-naturwissenschaftliche Klasse, Akademie der Wissenschaften in Wien, vol. 37, pp. 719-782, 1859.