Cite

1. All plain, darker at the top than the bottom gradually

MLA

1. All Plain, Darker at the Top than the Bottom Gradually. 0AD. https://collections.library.yale.edu/catalog/2033280.

APA, 6th edition

1. All plain, darker at the top than the bottom gradually. (0 C.E.). [Illustrations, Prints (Visual works)]. https://collections.library.yale.edu/catalog/2033280.