Answered By: Library Textbook and Publication Division
Last Updated: Oct 16, 2017    

The reasons are most likely including as followings:

  • The status has not updated on time on the website, such as out of stock, out of print, print on demand, etc.
  • Region sales restriction.
  • One book probably contains sensitive words, such as “history”, “political”, “map”, etc. according to relevant local regulations.

Other specific reasons will be updated after confirmation with publishers.