Heck, H. D. (1972). Lexikon der Technik. Goverts.
Chicago Style (17th ed.) CitationHeck, Hans Dieter. Lexikon Der Technik. Frankfurt a.M: Goverts, 1972.
MLA (9th ed.) CitationHeck, Hans Dieter. Lexikon Der Technik. Goverts, 1972.
Warning: These citations may not always be 100% accurate.