MLA

Hooke, Robert, 1635-1703. Letter : Gresham Colledg, London, to Sir Isaac Newton. GROUP 2583, folder F-1. 1679 Dec 9. https://collections.library.yale.edu/catalog/10171228.

APA, 6th edition

Hooke, Robert, 1635-1703. (["GROUP 2583, folder F-1"])(1679 Dec 9)[Letter : Gresham Colledg, London, to Sir Isaac Newton]. https://collections.library.yale.edu/catalog/10171228.