This list will always be incomplete.
I’m using links because I’m lazy. All the information you will need about the books you can find by clicking and source them as you like. I found a way to embed some of the books featured in Google Books, and if you know how to ZOOM in with your browser, you can read some of the following without even leaving this page.
A Complete Treatise on the Art of Singing
Observations on the Human Voice:
Proceedings of the Royal Society of London, Volume 7 – page 399
Hints On Singing by Manuel Garcia
Garcia: The Centenarian and His Times
Bel Canto: A History of Vocal Pedagogy
Manuel García (1775-1832) Chronicle of the Life of a bel canto Tenor at the Dawn of Romanticism
America’s Musical Inheritance – Memories And Reminiscences
On Playing the Flute – Johann Joachim Quantz
The following are not recommended for your home library, but you might request them at the public or university library if you want to see some of the negative stuff to which I make reference.
National Schools of Singing: English, French, German, and Italian Techniques of Singing Revisited
The Disciplines Of Vocal Pedagogy: Towards An Holistic Approach