Happy #EarthDay!
Books about Earth (Planet) -- Core -- Fiction at PG:
https://www.gutenberg.org/ebooks/subject/6593
Books about Earth (Planet) -- Fiction at PG:
https://www.gutenberg.org/ebooks/subject/35120
Books about Earth (Planet) -- Miscellanea at PG:
https://www.gutenberg.org/ebooks/subject/28395