The most common and most likely answer to this crossword clue is the 3 plus 7 letter word NON FICTION
I've seen this crossword clue in The Guardian
N
O
N
F
I
C
T
I
O
N
Buddy explains!
The straight part
We know that "such books" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case such books = non fiction.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NON FICTION mean?
NON FICTION noun- Written works intended to give facts, or true accounts of real things and events. Often used attributively.