1. G. S. Asanov, ?Finsler space with algebraic metric, defined by a frame field,? J. Sov. Math.,13, No. 5 (1980).
2. D. V. Beklemishev, ?Differential geometry of spaces with almost complex structure,? in: Geometry, 1963 [in Russian], Itogi Nauki Tekh. VINITI AN SSSR, Moscow (1965), pp. 165?212.
3. V. I. Bliznikas, ?Geometry of systems of first-order partial differential equations,? in: Memoirs of the Geometry Seminar [in Russian], Vol. 2, Inst. Nauchn. Inform. AN SSR (1969), pp. 33?53.
4. N. Bourbaki, Differentiable and Analytic Manifolds. Summary of Results [Russian translation], Mir, Moscow (1975).
5. V. V. Vagner, ?Two-dimensional space with cubic metric,? Uch. Zap. Saratov. Univ., Ser. Fiz.-Mat.,1, No. 1, 29?40 (1938).