• [1] Earl A. Coddington and Norman Levinson, Theory of ordinary differential equations, McGraw-Hill Book Company, Inc., New York-Toronto-London, 1955. MR 0069338
• [2] Lawrence M. Graves, The theory of functions of real variables, McGraw-Hill Book Company, Inc., New York-Toronto-London, 1956. 2d ed. MR 0075256
• [3] J. LaSalle, Uniqueness theorems and successive approximations, Ann. of Math. (2) 50 (1949), 722–730. MR 31165, https://doi.org/10.2307/1969559

Bibliography

[1]

E. A. Coddington and N. Levinson, Theory of ordinary differential equations, McGraw-Hill, New York, 1955. MR 0069338 (16:1022b)

[2]

L. M. Graves, The theory of functions of real variables, 2nd ed., McGraw-Hill, New York, 1956. MR 0075256 (17:717f)

[3]

J. LaSalle, Uniqueness theorems and successive approximations, Ann. of Math. 50 (1949), 722-730. MR 0031165 (11:110e)