MLA

Johnston, William Walker Whitehall, 1835-1886. Album Page 13. Verso, top: Portrait of an older boy and young girl; possibly Walter Mowbray Johnston or Francis Hope Johnston with Edith Harriet Elizabeth Johnston (born 1853). Box 1, folder 11. circa 1858. https://collections.library.yale.edu/catalog/10944300.

APA, 6th edition

Johnston, William Walker Whitehall, 1835-1886. (["Box 1, folder 11"])(circa 1858)[Album Page 13. Verso, top: Portrait of an older boy and young girl; possibly Walter Mowbray Johnston or Francis Hope Johnston with Edith Harriet Elizabeth Johnston (born 1853)]. https://collections.library.yale.edu/catalog/10944300.