Smithsonian Institution. (1918). Cambrian geology and paleontology, IV: No. 4, Appendages of trilobites. [publisher not identified].
Chicago Style (17th ed.) CitationSmithsonian Institution. Cambrian Geology and Paleontology, IV: No. 4, Appendages of Trilobites. [Washington]: [publisher not identified], 1918.
MLA (9th ed.) CitationSmithsonian Institution. Cambrian Geology and Paleontology, IV: No. 4, Appendages of Trilobites. [publisher not identified], 1918.
Warning: These citations may not always be 100% accurate.