/review/list/ not showing ISBNs

[Jason]

When I get a list of the books on my shelf using https://www.goodreads.com/review/list...

...all of the ISBNs are nil, like this:




I don't actually want the ISBN specifically, but I do want to be able to look up popular shelves for each book. Any ideas?

[Oleg]

isbn is not mandatory field. Check, if ISBN exists on books web pages