APA

Hughes N. C., . (1994). Ontogeny, intraspecific variation, and systematics of the Late Cambrian trilobite Dikelocephalus. Washington, D.C: Smithsonian Institution Press.

Chicago

Hughes Nigel C, . 1994. Ontogeny, intraspecific variation, and systematics of the Late Cambrian trilobite Dikelocephalus. Washington, D.C: Smithsonian Institution Press.

Harvard

Hughes N. C., . (1994). Ontogeny, intraspecific variation, and systematics of the Late Cambrian trilobite Dikelocephalus. Washington, D.C: Smithsonian Institution Press.

MLA

Hughes Nigel C, . Ontogeny, intraspecific variation, and systematics of the Late Cambrian trilobite Dikelocephalus. Washington, D.C: Smithsonian Institution Press. 1994.