1. V. P. Maslov, Theory of Perturbations and Asymptotic Methods [in Russian], Moscow State University, Moscow (1965).
2. V. P. Maslov, Operator Methods [in Russian], Nauka, Moscow (1973); English transl.: Operational Methods, Mir, Moscow (1976).
3. V. P. Maslov, The Complex WKB Method for Nonlinear Equations [in Russian], Nauka, Moscow (1977); English transl. (Progr. Phys., vol. 16), Birkhäuser, Basel (1994).
4. R. Jackiw, Rev. Modern Phys., 49, 681–706 (1977).
5. M. V. Karasev and V. P. Maslov, Nonlinear Poisson Brackets: Geometry and Quantization [in Russian], Nauka, Moscow (1991); English transl. (Transl. Math. Monogr., vol. 119), Amer. Math. Soc., Providence, R. I. (1993).