Theory of ordinary differential equations [by] Earl A. Coddington [and] Norman Levinson. Coddington, Earl A., 1920- Levinson, Norman, 1912- joint author. Differential equations. QA372 .C6 517.38201 COT New York, McGraw-Hill, 1955. 1955. 1955 Text 429 p. eng International series in pure and applied mathematics