Earl, J. M. (1968). Differential Equations. McGraw-Hill.
Cita Chicago (17th ed.)Earl, J. M. Differential Equations. London: McGraw-Hill, 1968.
Cita MLA (9th ed.)Earl, J. M. Differential Equations. McGraw-Hill, 1968.
Atenció: Aquestes cites poden no estar 100% correctes.