The earliest known verifiable listing of the film's release year is in the publication Horror and Science Fiction Films II by Donald C. Willis, copyrighted in 1982; in it, the film's release year is listed as "1980?".[1]Home video distributor
Vinegar Syndrome lists the film's release year with more certainty as 1980.[2] Several other sources list the film's release year as 1980.[3][4][5] In a 1985 volume of The Motion Picture Guide, the film's release date is listed as 1984.[6][ISBN missing] However, according to Canadian Film and Video: A Bibliography and Guide to the Literature, published in 1997, the film was released in 1979.[7]
^The earliest known verifiable listing of the film's release year dates it to around 1980. This is the year listed by the film's current distributor,
Vinegar Syndrome. See the
Release section for details.