It sounds like you're looking for a guide to locate or understand the so-called “Vocal Wisdom: Maxims of Giovanni Battista Lamperti” — likely in PDF format.
Legato and Messa di Voce: True vocal art is founded on the ability to maintain a perfect legato—the seamless binding of tones. He used the messa di voce (swelling and diminishing a note) as the ultimate test of a singer's control over breath and resonance. vocal wisdom lamperti pdf
One of Lamperti’s most famous lines is: “He who knows how to breathe and to pronounce well, knows how to sing.” It sounds like you're looking for a guide
Appoggio (Breath Support): One of Lamperti’s most critical concepts is the appoggio, or the "leaning" of the voice on the breath. He advocated for a condition of internal pressure where the body resists expansion, often described as "pelvic control" of the breath, where support is felt low in the torso. The #1 Rule from Vocal Wisdom (Read this
Lamperti's treatise has had a profound impact on vocal pedagogy, influencing generations of singing teachers and vocalists. His work has been widely adopted and respected, and his principles continue to guide vocalists in achieving technical excellence and artistic expression.