Complex sentence: Deathworld is the name of a trilogy of science fiction novels by Harry Harrison consisting of the books "Deathworld" (first published 1960, anthologized in Astounding Science Fiction), "Deathworld 2" (1964) and "Deathworld 3" (1968).
Split into simpler sentences: Deathworld is the name of a trilogy of science fiction novels by Harry Harrison. The trilogy consists of the books "Deathworld" (first published 1960, anthologized in Astounding Science Fiction), "Deathworld 2" (1964) and "Deathworld 3" (1968).