In the Library Company’s collection:
Birkhead, Tim. The Wonderful Mr. Willughby: The First True Ornithologist. Bloomsbury Press, 2018.
Philosophical letters between the Late Learned Mr. Ray and Several of his Ingenious Correspondents, … To Which are Added Those of Francis Willughby Esq, London: printed by William and John Innys, 1718.
Ray, John. Historia Insectorum. London: A.& J Churchill, 1710. The text of Ray’s Methodus Insectorum of 1705 is reprinted as a prolegomena to this work.
Ray, John. Observations Topographical, Moral, & Physiological; Made in a Journey through Part of the Low-Countries, Germany, Italy, and France … Whereunto is Added a Brief Account of Francis Willughby Esq; His Voyage through a Great Part of Spain. London: printed for John Martyn, printer to the Royal Society, at the Bell in St. Paul’s Church-yard, 1673.
Wilkins, John. An Essay towards a Real Character, and a Philosophical Language. London: printed for Sa: Gellibrand, and for John Martyn, printer to the Royal Society, 1668.
Willughby, Francis. De Historia Piscium Libri Quatuor. Oxford: Sheldonian Theatre, 1686.
Willughby, Francis. The Ornithology of Francis Willughby of Middleton in the County of Warwick Esq; fellow of the Royal Society. London: printed by A. C. for John Martyn, printer to the Royal Society, at the Bell in St. Paul’s Church-Yard, 1678.
Baldner, Leonard. Vogel, Fisch- und Thierbuch. 1666.
Harrington, Kat. “Pepys and the Royal Society.” 17 December 2015. https://blogs.royalsociety.org/history-of-science/2015/12/17/pepys-royal-society/
Ogilvie, Brian W. “Attending to insects: Francis Willughby and John Ray.” Notes and Records of the Royal Society of London, December 20, 2012, 66(4): 357–372. Published online October 10, 2012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3594893/
“Ray (Wray), John”, Encyclopaedia Britannica, v.18, Encyclopaedia Britannica, Inc., 1973.
“Willughby, Francis (1635-1672)”, pp. 54-57, Dictionary of National Biography, 1885-1900, Volume 62 by George Simonds Boulger in Wikisource: https://en.wikisource.org/wiki/Willughby,_Francis_(DNB00)