MLA

Johnston, William Walker Whitehall, 1835-1886. Album Page 66. Verso: Black man posed standing with two pack mules, with an enlisted man from the 1st West India Regiment in the background, probably at Saint Lucia. Box 1, folder 64. circa 1860. https://collections.library.yale.edu/catalog/33086930.

APA, 6th edition

Johnston, William Walker Whitehall, 1835-1886. (["Box 1, folder 64"])(circa 1860)[Album Page 66. Verso: Black man posed standing with two pack mules, with an enlisted man from the 1st West India Regiment in the background, probably at Saint Lucia]. https://collections.library.yale.edu/catalog/33086930.