Sources:

Rateliff, John D., The History of the Hobbit. E-book ed., HarperCollinsPublishers. Apple Books.

Swank, Kris, The Hobbit and The Father Christmas Letters, Mythlore: A Journal of J.R.R. Tolkien, C.S. Lewis, Charles Williams, and Mythopoeic Literature: Vol. 32 : No. 1 , Article 9. 2013
Available at: https://dc.swosu.edu/mythlore/vol32/iss1/9  (Accessed Nov 25, 2019)

Tolkien, J. R. R., Letters from Father Christmas. edited by Baillie Tolkien. E-book ed., Houghton Mifflin Harcourt. Apple Books.

Tolkien, J. R. R., The Fellowship of the Ring. E-book ed., HarperCollins e-books. Apple Books.

Tolkien, J. R. R., The Hobbit: or There and Back Again. E-book ed., HarperCollins e-books. Apple Books.

Tolkien, J. R. R., The Nature of Middle-earth, edited by Carl F. Hostetter. E-book ed., HarperCollinsPublishers, 2021. Apple Books.

Tolkien, John and Priscilla Tolkien, The Tolkien Family Album. Houghton Mifflin Company, Boston, 1992. 

Tolkien Gateway entry for “Beorn”

https://tolkiengateway.net/wiki/Beorn

(Accessed Dec 20, 2021)