MLA
Pettengill, S. B. (Samuel Barrett), 1839-1909. The college cavaliers : a sketch of the service of a company of college students in the Union army in 1862 /. 1883. Regimental Histories. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/849t1g1q7r-cor.
APA, 6th edition
Pettengill, S. B. (Samuel Barrett), 1839-1909. (1883)[The college cavaliers : a sketch of the service of a company of college students in the Union army in 1862 /]. Regimental Histories, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/849t1g1q7r-cor.
Chicago
Pettengill, S. B. (Samuel Barrett), 1839-1909, The college cavaliers : a sketch of the service of a company of college students in the Union army in 1862 /, 1883, Regimental Histories, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/849t1g1q7r-cor.