My teachers have been:  

Philip Eve, Ken Tamplin, Craig Sirianni (student of Tom Lomonaco), Daniel Formica (a grand-student of Arrigo Pola, Pavarotti's teacher), Donna Reid, John-Paul Miles, Guy Babusek, Kegan DeBoheme, Karmyn Tyler Cobb (who teaches Gary Catona's method), Natasha Đikanović de Comas, Matt Sky. 

I've also studied the methods of Cornelius Reid, Anthony Frisell, Gary Catona, Berton Coffin, Richard Miller, Eric Arseneaux, Roger Love, Seth Riggs, Brett Manning, Michael Trimble, Marnell Sample and a great many more.