Lange, Eva C. German in 20 lessons, intended for self-study and for use in schools : : with a simplified system of phonetic pronunciation : based on the method of R. Diez de la Cortina / [electronic resource] / by Eva C. Lange.. — 7th ed. completely rev.. — New York : Garden City, N.Y. : : R.D. Cortina Co. ; : Distributors, Doubleday,, 1977.. — 360 p. : : ill. ; 21 cm. — (Cortina method)(A Dolphin book).
First-6th ed. published under title: Cortina's German in 20 lessons.