Question: What producer who died in 1978 developed American television detective show Mannix?

Context paragraphs:
Levinson &amp; Link: Richard Levinson and William Link were television producers and writers who collaborated for 43 years, until Levinson's death.  They created classic television detective series such as "Columbo", "Mannix", "Ellery Queen", "Murder, She Wrote" and "Scene of the Crime", as well as made-for-TV movies including "The Gun", "My Sweet Charlie", "That Certain Summer", "The Judge and Jake Wyler", "The Execution of Private Slovik", "Charlie Cobb: A Nice Night for a Hanging", "Rehearsal for Murder", and "Blacke's Magic".  They also collaborated on two feature films: "The Hindenburg" (1975) and "Rollercoaster" (1977).

Bruce Geller: Bruce Bernard Geller (October 13, 1930 – May 21, 1978) was an American lyricist, screenwriter, director, and television producer.

Gail Fisher: Gail Fisher (August 18, 1935 – December 2, 2000) was an American actress who was one of the first black women to play substantive roles in American television.  She was best known for playing the role of secretary Peggy Fair on the television detective series "Mannix" from 1968 through 1975, a role for which she won two Golden Globe Awards and an Emmy Award; she was the first black woman to win either award.  She also won an NAACP Image Award in 1969.

List of Mannix episodes: The following is a list of episodes for the detective television series "Mannix" which aired from 1967 to 1975 in the United States on the CBS television network.  The title character, Joe Mannix, is an Armenian-American private investigator played by Mike Connors (who was also of Armenian heritage).  "Mannix" was created by Richard Levinson and William Link and developed by executive producer Bruce Geller (who also created "").

La Chica de Ayer (TV series): La Chica de Ayer (English: "The Girl from Yesterday") is a Spanish television series which first aired on the channel Antena 3 between 26 April and 14 June 2009.  A detective show, it was based on the British series "Life on Mars" which featured a policeman suddenly transported back to 1973.  The Spanish version of the show was set four years later, in 1977, and took its name from the Spanish song "La Chica de Ayer" by Nacha Pop in a similar manner to the British version which was named after the David Bowie song "Life on Mars? ".  It featured Ernesto Alterio in the role of Samuel Santos, a modern-day police officer who finds himself in 1977 post-Franco Spain under the command of Quin Gallardo (Antonio Garrido), a tough old-school policeman contemptuous of his modern methods.

Burke's Law (1963 TV series): Burke's Law is an American detective series that aired on ABC from 1963 to 1966.  The show starred Gene Barry as Amos Burke, millionaire captain of Los Angeles police homicide division, who was chauffeured around to solve crimes in his 1962 Rolls-Royce Silver Cloud II.  The original series was converted from a detective show to a spy drama, Amos Burke Secret Agent, in its third and final season.  The series was revived in 1994–95 on CBS with Barry again playing Burke having returned to detective work.

Nick Dennis: Nick Dennis (April 26, 1904 – November 14, 1980) was a Greek American film actor born in Thessaly, Greece.  The supporting actor, who began in films in 1947, was known for playing ethnic types (usually Greek) in films such as "Kiss Me Deadly" and the Humphrey Bogart film "Sirocco".  Dennis, who spoke Greek fluently, appeared in a number of television programs in the 1960s and 1970s including playing the parts of Orderly Nick Kanavaras on the medical drama "Ben Casey" and Uncle Constantine on the detective show "Kojak".

Mannix: Mannix is an American television detective series that ran from 1967 to 1975 on CBS.  Created by Richard Levinson and William Link and developed by executive producer Bruce Geller, the title character, Joe Mannix, is a private investigator.  He is played by Mike Connors.

Explorations (Louis Bellson album): Explorations is an album by Argentine composer, pianist and conductor Lalo Schifrin and American drummer Louis Bellson recorded in 1964 and released on the Roulette label.  It was the first album composed entirely by Schifrin and features themes that would later be used in the television detective series "Mannix".

Claus Theo Gärtner: Claus Theo Gärtner (born 19 April 1943) in Berlin, Germany is a German television actor mainly known for his role as Josef Matula, the main character in the German detective show series "Ein Fall für Zwei" ("A Case For Two").

Supporting paragraphs: Mannix Bruce Geller
Answer: Bruce Geller