If you are interested in visiting the book's page at Cappelen Damm (in Norwegian) -- click here!
Below are the ISBN book numbers if you'd like to search for merchants who are selling the Norwegian editions.
Heftet (paperback) - ISBN: 9788202492489 (available September 24, 2015)
Innbundet (hardcover) - ISBN: 9788202447397 (available now)
eBook - ISBN: 9788202448226 (Epub format) (available now)