How can I repair splits in paperback binding like this? Is there a technique beyond just sticking some PVA glue in there? (I tried this and it didn't work too well!)

3 Ways to Repair a Book's Binding - wikiHow

advice to repair spine separation : r/bookbinding

3 Ways to Repair a Book's Binding - wikiHow

What glue is good for repairing damaged books? - Quora

Is there any way I can fix this crease? : r/bookbinding

Book Repair on a Budget: Consolidating a Textblock

What glue is good for repairing damaged books? - Quora

How can glue be removed from a page in a book? - Quora

3 Ways to Repair a Book's Binding - wikiHow

Just Open My New Book and it Seem the Glue is Already Coming Away

3 Ways to Repair a Book's Binding - wikiHow