What producer who died in 1978 developed American television detective show Mannix?
Mannix:  Created by Richard Levinson and William Link and developed by executive producer Bruce Geller, the title character, Joe Mannix, is a private investigator. Bruce Geller: Bruce Bernard Geller (October 13, 1930 – May 21, 1978) was an American lyricist, screenwriter, director, and television producer.
Bruce Geller