MLA

Magnus, Charles, and printmaker. Campbell U.S. Genl. Hospital, Washington, D.C. [Graphic]. Published by Chas. Magnus 12 Frankfort St. New York & 520 Seventh St. Washington, D.C., Entered according to Act of Congress A.D. 1864 by Chas. Magnus in the Clerks Office of the Southern District of N.Y., 1864. https://collections.library.yale.edu/catalog/17339434.

APA, 6th edition

Magnus, C., & printmaker. (1864). Campbell U.S. Genl. Hospital, Washington, D.C. [graphic] [Chromolithographs]. Published by Chas. Magnus 12 Frankfort St. New York & 520 Seventh St. Washington, D.C., Entered according to Act of Congress A.D. 1864 by Chas. Magnus in the Clerks Office of the Southern District of N.Y. https://collections.library.yale.edu/catalog/17339434.