Kashiwara, M; Vergne, M. On the Segal–Shale–Weil representation and harmonic polynomials (англ.) // Inventiones Mathematicae : journal. — 1978. — Vol. 44. — P. 1—47. — doi:10.1007/BF01389900.
Aubert Diagneault (2005) "Standard Cosmology and Other Possible Universes", chapter 13 of Physics Before
and After Einstein, M.M. Capria editor, IOS Pressdoi:10.3233/978-1-58603-462-7-285