Links for the "Book of Vaadin" (Chinese edition) are broken

General
1

In the page of “Book of Vaadin”:
https://vaadin.com/book

There is Chinese translation, but the links for PDF format, and Pocket PDF format are broken

2

The links for French and Spanish translations, PDF format, are broken too

3

Those PDF links seem to be working just fine for me at least. It just takes a while to load since the PDFs are rather large. Are you still unable to load them? If so, what OS and browser are you using?