Hello everyone,

My name is Will, and I am posting here for the very first time.

I have a small and modest collection of Tolkien's works, and recently acquired The Return of the King in a secondhand bookstore. To be specific, it is the first authorised US edition of The Lord of the Rings, published by Ballantine between 1965 and 1973. I managed to acquire the third book, and wanted to complete the collection with the purchasing of the first two.

However, I must have made a mistake on Abebooks.com, because they sent me the Ballantine edition published between 1981 and 1983. For reference purposes, here are the editions that I am referring to:

Ballantine, 1965-1973:
https://www.tolkienguide.com/modules/wiwimod/index.php?page=BallantineLOTR1
Ballantine, 1981-1983:
https://www.tolkienguide.com/modules/wiwimod/index.php?page=BallantineSweet1

I went through the copy of the Ballantine, 1965-1973 edition and I cannot seem to find the ISBN number. As such, I have been unable to purchase the first two books to complete the collection! It will be of tremendous help if someone here were to point me in the right direction! From my understanding, the particular edition that I want was released separately and in a box at the very same time, so maybe that's why my copy does not come with an ISBN? I have no idea how it works.

Please help! You are my only hope!