Man’ko, V. I. The symplectic group and invariants of quantum systems. (English) Zbl 0612.58042 J. Sov. Math. 36, 673-699 (1987). MSC: 37N99 81Q05 22E70 PDF BibTeX XML Cite \textit{V. I. Man'ko}, J. Sov. Math. 36, 673--699 (1987; Zbl 0612.58042) Full Text: DOI OpenURL
Maslov, V. P.; Chebotarev, A. M. Second term of the logarithmic asymptotics of path integrals. (English) Zbl 0558.28009 J. Sov. Math. 23, 2580-2598 (1983). MSC: 28C20 35K10 60B05 60J99 PDF BibTeX XML Cite \textit{V. P. Maslov} and \textit{A. M. Chebotarev}, J. Sov. Math. 23, 2580--2598 (1983; Zbl 0558.28009) Full Text: DOI OpenURL