MLA

Day & Son, Simpson, William, 1823-1899. Sebastopol from the sea. Undated. https://collections.library.yale.edu/catalog/2044066.

APA, 6th edition

Day & Son, & Simpson, William, 1823-1899. (Undated)[Sebastopol from the sea]. https://collections.library.yale.edu/catalog/2044066.