- Author: Schaefer R.
- Language: English
- Year: 2007
- Author: Cheah Ch.H. Schaefer K.
- Language: English
- Year: 2004
- Author: Шефер К. (Clemens Schaefer)
- Language: Русский
- Year: 1934
Technische Optik
djvu
- Author: Schaefer E.
- Language: German
- Year: 1997