Letters... [etc.]
MLA
Hippocrates. Letters... [Etc.]. 0AD. https://collections.library.yale.edu/catalog/16960300.
APA, 6th edition
H. (0 C.E.). Letters... [etc.] [Early works to 1800, Armorial bookplates, Illuminated manuscripts]. https://collections.library.yale.edu/catalog/16960300.