Do you mean:
* Books about SASS (the programming language)? There isn't a specific book series dedicated solely to Sass. However, there are many resources and books that cover Sass, including:
* Sass for Designers by Ben Frain
* Sass and Compass for Designers by Ben Frain
* Sass and Compass: The Definitive Guide by Lynn Beighley
* Learning Sass by Mark Goodyear
* Books that feature a character named "SASS"? There could be many books with characters named "SASS," but without more context, it's impossible to list them.
* A specific series you have in mind? If you remember any details about the series, like genre, cover art, or a specific title, please share them.
Once you provide more information, I can help you find the names and authors of the books you're looking for.