Cite

"Purcell, Pelham Humfrey and Blow autograph MSS", [ca. 1680].

MLA

"Purcell, Pelham Humfrey and Blow Autograph MSS", [Ca. 1680]. 0AD. https://collections.library.yale.edu/catalog/2007125.

APA, 6th edition

"Purcell, Pelham Humfrey and Blow autograph MSS", [ca. 1680]. (0 C.E.). https://collections.library.yale.edu/catalog/2007125.