The Bjorling Sound, Stephen Hastings
Though I am familiar with a number of books about singers, I know of no vocal study to rival the intense and illuminating new book on Jussi Bjorling by Stephen Hastings.
Clayton, Dr. William C.
"The Bjorling Sound by Stephen Hastings,"
Newsletter of the Jussi Björling Societies of the USA & UK: Vol. 22
, Article 2.
Available at: https://scholarsarchive.byu.edu/jussibjorlingsocietynl/vol22/iss1/2