Anné, Colette, and Anne-Marie Charbonnel. “Bohr-Sommerfeld Conditions for Several Commuting Hamiltonians”. CUBO, A Mathematical Journal 6, no. 2 (August 1, 2004): 15–34. Accessed October 12, 2025. https://cubo.ufro.cl/index.php/cubo/article/view/1638.