Premise: Detective Hieronymus 'Harry' Bosch (pronounced "He-ron-ee-mus" "Bosh") is a Fictional character created by American author Michael Connelly. Bosch debuted as the lead character in the 1992 novel "The Black Echo", the first in a best-selling police procedural series now numbering twenty-one novels.
Hypothesis: The novel "The Black Echo" was released in nineteen hundred ninety one.