Litteratur
C. Henry Edwards and David E. Penney: Elementary Diffential Equations with Boundary Value Problems, 5th ed., 2004. Prentice Hall. ISBN: 0-13-145773-X (hardbound) or 0-13-129346-X (softbound). Prentice Hall.
C. Henry Edwards and David E. Penney: Elementary Differential Equations with Boundary Value Problems, 6th ed., 2008. Prentice Hall. ISBN: 0136006132. Prentice Hall.
George F. Simmons: Differential Equations with Applications and Historical Notes, 2nd ed.,