• [1] L. Ahlfors, On quasi-conformal mappings, Journal d'Analyse Mathématique vol. 3 (1954) pp. 1-58, 207-208.
• [2] H. Cartan, Algebraic topology, Mimeographed notes, Harvard University, 1949.
• [3] E. Cartan, Leçons sur les invariants integraux, Paris, 1922.
• [4] Shiing-shen Chern, Philip Hartman, and Aurel Wintner, On isothermic coordinates, Comment. Math. Helv. 28 (1954), 301–309. MR 0066718, https://doi.org/10.1007/BF02566936
• [5] G. Evans, An elliptic system corresponding to Poisson's equation, Acta Literarum ac Scientiarum (Szeged) vol. 6 (1932-1934) pp. 27-33.
• [6] Philip Hartman, On the local uniqueness of geodesics, Amer. J. Math. 72 (1950), 723–730. MR 0038111, https://doi.org/10.2307/2372288
• [7] Philip Hartman and Aurel Wintner, On the fundamental equations of differential geometry, Amer. J. Math. 72 (1950), 757–774. MR 0038110, https://doi.org/10.2307/2372293
• [8] Philip Hartman and Aurel Wintner, On the asymptotic curves of a surface, Amer. J. Math. 73 (1951), 149–172. MR 0040739, https://doi.org/10.2307/2372167
• [9] Philip Hartman and Aurel Wintner, On the local behavior of solutions of non-parabolic partial differential equations, Amer. J. Math. 75 (1953), 449–476. MR 0058082, https://doi.org/10.2307/2372496
• [10] Philip Hartman and Aurel Wintner, Regular binary Pfaffians and nonparabolic partial differential equations, Rend. Circ. Mat. Palermo (2) 3 (1954), 347–362 (1955). MR 0075635, https://doi.org/10.1007/BF02849265
• [11] M. Lavrentieff, A fundamental theorem of the theory of quasi-conformal mappings of -dimensional regions, Bull. Acad. Sci. URSS. Ser. Math. vol. 12 (1948) pp. 513-514; Amer. Math. Soc. Translations, no. 29.
• [12] Charles B. Morrey Jr., On the solutions of quasi-linear elliptic partial differential equations, Trans. Amer. Math. Soc. 43 (1938), no. 1, 126–166. MR 1501936, https://doi.org/10.1090/S0002-9947-1938-1501936-8
• [13] -, Multiple integral problems in the calculus of variations and related topics, Berkeley, 1943.
• [14] Louis Nirenberg, On nonlinear elliptic partial differential equations and Hölder continuity, Comm. Pure Appl. Math. 6 (1953), 103–156; addendum, 395. MR 0064986, https://doi.org/10.1002/cpa.3160060105
• [15] Aurel Wintner, Remarks on binary Riemannian metrics, Rend. Circ. Mat. Palermo (2) 5 (1956), 59–72. MR 0079307, https://doi.org/10.1007/BF02849271
• [1] Philip Hartman and Aurel Wintner, On the curvatures of a surface, Amer. J. Math. 75 (1953), 127–141. MR 0052170, https://doi.org/10.2307/2372622
• [2] Philip Hartman and Aurel Wintner, On asymptotic parametrizations, Amer. J. Math. 75 (1953), 488–496. MR 0057594, https://doi.org/10.2307/2372498
• [3] V. Hlavaty, Differentialgeometrie, Groningen, 1939.
• [4] Aurel Wintner, On the local role of the theory of the logarithmic potential in differential geometry, Amer. J. Math. 75 (1953), 679–690. MR 0061436, https://doi.org/10.2307/2372542
• [5] Aurel Wintner, On indefinite binary Riemannian metrics, Amer. J. Math. 77 (1955), 853–867. MR 0075642, https://doi.org/10.2307/2372602

Bibliography

[1]

L. Ahlfors, On quasi-conformal mappings, Journal d'Analyse Mathématique vol. 3 (1954) pp. 1-58, 207-208.

[2]

H. Cartan, Algebraic topology, Mimeographed notes, Harvard University, 1949.

[3]

E. Cartan, Leçons sur les invariants integraux, Paris, 1922.

[4]

S. S. Chern, P. Hartman and A. Wintner, On isothermic coordinates, Comment. Math. Helv. vol. 28 (1954) pp. 301-309. MR 0066718 (16:622e)

[5]

G. Evans, An elliptic system corresponding to Poisson's equation, Acta Literarum ac Scientiarum (Szeged) vol. 6 (1932-1934) pp. 27-33.

[6]

P. Hartman, On the local uniqueness of geodesics, Amer. J. Math. vol. 72 (1950) pp. 723-730. MR 0038111 (12:357b)

[7]

P. Hartman and A. Wintner, On the fundamental equations of differential geometry, ibid. vol. 72 (1950) pp. 757-774. MR 0038110 (12:357a)

[8]

-, On the asymptotic curves of a surface, ibid. vol. 73 (1951) pp. 149-172. MR 0040739 (12:742d)

[9]

-, On the local behavior of solutions of non-parabolic partial differential equations, ibid. vol. 76 (1954) pp. 449-476. MR 0058082 (15:318b)

[10]

-, Regular binary Pfaffians and non-parabolic partial differential equations, Rend. Circ. Mat. Palermo vol. 3 (1954) pp. 347-362. MR 0075635 (17:781e)

[11]

M. Lavrentieff, A fundamental theorem of the theory of quasi-conformal mappings of -dimensional regions, Bull. Acad. Sci. URSS. Ser. Math. vol. 12 (1948) pp. 513-514; Amer. Math. Soc. Translations, no. 29.

[12]

C. B. Morrey, On the solutions of quasi-linear elliptic partial differential equations, Trans. Amer. Math. Soc. vol. 43 (1938) pp. 126-166. MR 1501936

[13]

-, Multiple integral problems in the calculus of variations and related topics, Berkeley, 1943.

[14]

L. Nirenberg, On nonlinear partial differential equations and Hölder continuity, Communications on Pure and Applied Mathematics vol. 6 (1953) pp. 103-156. MR 0064986 (16:367c)

[15]

A. Wintner, Remarks on binary Riemannian metrics, Rend. Circ. Mat. Palermo vol. 5 (1956) pp. 59-72. MR 0079307 (18:66d)

[1]

P. Hartman and A. Wintner, On the curvatures of a surface, Amer. J. Math. vol. 75 (1953) pp. 127-141. MR 0052170 (14:583a)

[2]

-, On asymptotic parametrizations, ibid. vol. 75 (1953) pp. 488-496. MR 0057594 (15:252h)

[3]

V. Hlavaty, Differentialgeometrie, Groningen, 1939.

[4]

A. Wintner, On the local role of the theory of the logarithmic potential in differential geometry, Amer. J. Math. vol. 75 (1953) pp. 679-690. MR 0061436 (15:826c)

[5]

-, On indefinite binary Riemannian metrics, ibid. vol. 77 (1955) pp. 853-867. MR 0075642 (17:782e)