The question of when to get rid of a book (or books) is one that often causes a bibliophile many a heart palpitation. It may even seem bad form to even contemplate the question, let alone ask it in a blog (especially when the person doing the asking is a fellow bibliophile.
The link below is to an article that takes a look at this very question, with some worthwhile advice.
For more visit:
http://bookriot.com/2017/06/27/when-to-get-rid-of-books/