Franklin

MLA

Willam, Horst Alexander. Carl Zeiss, 1816-1888. München: Bruckmann, 1967.

APA

Willam, H. Alexander. (1967). Carl Zeiss, 1816-1888. München: Bruckmann.

Chicago

Willam, Horst Alexander. Carl Zeiss, 1816-1888. München: Bruckmann, 1967.