Hentosh, Oksana E, Yarema A Prykarpatsky, Alexandr Balinsky, and Anatolij K Prykarpatski. “The Dispersionless Completely Integrable Heavenly Type Hamiltonian Flows and Their Differential-Eometric Structure”. Annals of Mathematics and Physics 2, no. 1 (August 28, 2019): 011–025. Accessed August 10, 2025. https://www.mathematicsgroup.com/amp/article/view/AMP-2-106.