Παραπομπή σε μορφή APA (7η εκδ.)

ETGEN, G. J. (1977). An Introduction to ordinary differential: Equations with difference equations, numerical methods and applications. Harper and Row.

Παραπομπή σε μορφή Chicago (17η εκδ.)

ETGEN, Garret J. An Introduction to Ordinary Differential: Equations with Difference Equations, Numerical Methods and Applications. New York: Harper and Row, 1977.

Παραπομπή σε μορφή MLA (9th εκδ.)

ETGEN, Garret J. An Introduction to Ordinary Differential: Equations with Difference Equations, Numerical Methods and Applications. Harper and Row, 1977.