I’m selling these two issues of Swamp Thing reprinted by National Book Store most likely in the late 1970s or the early 1980s. (Click on the images to see higher-resolution versions of them.) Each has 20 pages and the inner covers are NBS advertisements like the outer back cover.
Issue 24 was pencilled by Ernie Chan and inked by Fred Carrillo, both Filipinos. It has an 18-page story (The Earth Below), a 1-page advertisement for DC comics (Superman and Batman), and a 1-page letters page (Swamp Things). It is the last issue in the series. (According to the Grand Comics Database, “A 25th issue was written and illustrated, featuring an encounter between Swamp Thing and Hawkman, but the series was cancelled and it was never published.”)