Lange, E. C. (1962). German in 20 lessons, intended for private study and for use in schools: With a new system simplified phonetic pronunciation : based on the method of R. Diez de la Cortina (Seven Edition.). R. D. Cortina Co. ; distributors, Doubleday.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Lange, Eva C. German in 20 Lessons, Intended for Private Study and for Use in Schools: With a New System Simplified Phonetic Pronunciation : Based on the Method of R. Diez De La Cortina. Seven Edition. New York : Garden City, N.Y.: R. D. Cortina Co. ; distributors, Doubleday, 1962.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Lange, Eva C. German in 20 Lessons, Intended for Private Study and for Use in Schools: With a New System Simplified Phonetic Pronunciation : Based on the Method of R. Diez De La Cortina. Seven Edition. R. D. Cortina Co. ; distributors, Doubleday, 1962.