L.M. Abatangelo, On totally umbilical submanifolds of locally Minkowski manifold, Collect. Math. 43 (1992), no. 2, 151--175.
H. Akbar-Zadeh, Initiation to Global Finslerian Geometry, Vol. 68, Elsevier Science, 2006.
D. Bao, S. Chern and Z. Shen, An introduction to Riemann-Finsler Geometry. Grad. Texts in Math. 200, Springer, 2000.
A. Bejanco and H.R. Farran, Geometry of pseudo-Finsler submanifolds, Kluwer Acad. Publ., Dordrecht, 2000.
B. Bidabad, A classification of complete Finsler manifolds through the conformal theory of curves, Differential Geom. Appl. 35 (2014) 350--360.
B. Bidabad and Z. Shen, Circle-preserving transformations in Finsler spaces, Publ. Math. Debrecen, 81 (2012), no. 3-4, 435--445.
I. Bucataru and R. Miron, Finsler-Lagrange Geometry, Applications to Dynamical Systems, Editura Academiei Române, Bucuresti, 2007.
Q. He, W. Yang and W. Zhao, On totally umbilical submanifolds of Finsler spaces, Ann. Polon. Math. 100 (2011), no. 2, 147--157.
S. Kobayashi and K. Nomizu, Foundations of Differential Geometry, Vol. I, Vol. II, Wiley-Interscience, New York, 1963, 1969.
J. Li, Umbilical hypersurfaces of Minkowski spaces, Math. Commun. 17 (2012), no. 1, 63--70.
K. Nomizu, Generalized central spheres and the notion of spheres in Riemannian geometry, Tohoku Math. J. 25 (1973) 129--137.
K. Nomizu and K. Yano, On circles and spheres in Riemannian geometry, Math. Ann. 210 (1974), no. 2, 163--170.
M.K. Sedaghat and B. Bidabad, The Axiom of Spheres in Finsler Geometry, Annals Un. Al. I. Cuza Iasi Mat. 3 (2016), no. 8, 883--890.
M.K. Sedaghat and B. Bidabad, On a class of complete Finsler manifolds, Internat. J. Math. 26 (2015), no. 10, Article ID 1550091, 9 pages.
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