Hentosh O. E.; Prykarpatskyy Y. A.; Balinsky A. A.; Prykarpatski A. K. Geometric structures on the orbits of loop diffeomorphism groups and related “heavenly-type” Hamiltonian systems. I. Ukrains’kyi Matematychnyi Zhurnal, v. 74, n. 8, p. 1029 - 1059, 4 Oct. 2022.