Welcome to the forum!
It depends on how you want to approach this. I play the White side of the exchange and own an excellent book by Kindermann (The Spanish Exchange Variation - Edition Olms). It has a small introduction on the main themes and the pawn endgame (White's dream) and then goes on to present all the main lines (warning: this is the main part of the book and it gets quite theoretical, however I believe you first need to play through some of the games and avoid focusing on memorizing
any lines / the plus side is that you will have a good reference book for many-many years).
The book's layout is very good (the detailed index of lines is also very helpful), only one small annoying thing: captures, checks, etc. are not mentioned, ie.: instead of 1. KxNf3 Qxg3+ you see 1. Kf3 Qg3 (at least it's all in figurines iirc). There is also a PGN somewhere on the internet with all the lines in the book, which is helpful if you plan to read this book while using Chessbase.
An older book - Mastering the Spanish - Ponzetto & King, has also a good chapter on the exchange (theory there is less updated though / this again is not such a problem for me: I still play the 'older' lines instead of the modern ones recommended by Kindermann). This is a hard to find book, however if you play the Spanish with both colours, this is a very good buy and a very easy book to read.
A 3rd source I have consulted was Fischer's 60 Memorable Games, where he includes some notes on the Spanish Exchange, esp. in his game against Gligoric.
There are some other books on the market but have never seen or read them so maybe someone else can inform you about them. It would be also helpful if you told us your current level, e.g. if below 1700 I would say go for 'Mastering the Spanish', if above 1700 try Kindermann's book.
This is my 2c