In 1987, the Robotech animated series was adapted into novel form by authors James Luceno and Brian Daley and published by Del Rey Books. Having previously collaborated on the animated series Galaxy Rangers, the pair's Robotech novels were released under the unified pseudonym of "Jack McKinney". Using fictitious epigraphs in the style of Dune, McKinney's novels escaped the limitations inherent in the dubbed cartoon and fleshed out its chronology in greater detail; most significantly, by adapting the storyline of the aborted sequel project, "The Sentinels". The entire series lasted for twenty-one books, the first fifteen of which were later collected into five three-book omnibus compilations in the early 1990s.