MLA

Simpson, Randolph Linsly, 1927-1992. Army order "Vicksburg, Miss., March 11th, 1864, Orders, No. 7" -concerning the principles of numbering of regiments of troops of African descent L. Thomas, Adjutant General. Two pages from a bound volume 7-3/4 x 5. Box 37, folder 1163. undated. https://collections.library.yale.edu/catalog/2005517.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 37, folder 1163"])(undated)[Army order "Vicksburg, Miss., March 11th, 1864, Orders, No. 7" -concerning the principles of numbering of regiments of troops of African descent L. Thomas, Adjutant General. Two pages from a bound volume 7-3/4 x 5]. https://collections.library.yale.edu/catalog/2005517.