If you know science-fiction, you’ve definitely heard of Edgar Rice Burroughs! He was an American writer best known for his Tarzan books, along with his John Carter of Mars series and Carson Napier of Venus series.
The Tarzan books are all from Ballentine Books and the three Venus books are from Ace Science Fiction Classics. All have little wear other than the previous owners name stamped on the first page and his initials markered on the spine.
Tarzan books measure 4 1/4” wide by 7 1/4” tall. Venus books measure 4 1/8 wide by 6 1/4” tall.