This series is composed of mostly unrelated titles of various genres, but they are clearly intended to be a series due to the numbering. Early issues have no obvious collective series title (and no title in the indicia). They are simply labeled "Series 1 No. 1", generally alongside the "Planet Comics" branding. The title here ("Planet Series") is taken from later "Murray Comics" branded issues that include a title, "Planet Series 3 No. 1". For the purpose of logging these issues into GCD, the three "series" are treated as three volumes. The common thread for these issues is that they reprint non-DC stories, mainly Charlton, by a publisher mainly known for it's DC reprints. It is possible that the series functioned as a "try out" forum, but there doesn't seem to be an obvious link between the single issues and titles that became their own series.