Reddit reviews World Trigger, Vol. 1 (1)

Well this is 4 months late but just so you know for the future you can post direct links to manga volumes from the amazon store on /r/manga but it just cannot have a referral link in the URL.

For amazon the referral links are usually at the end and are something like

ref=sr_X2_5?ie=UXX8&qid=224XX031590

So a linking to volumes on Amazon is allowed the link just needs to be something like

http://www.amazon.com/World-Trigger-Vol-Daisuke-Ashihara/dp/142157764X

You could also shorten it even more to

http://www.amazon.com/dp/142157764X

They don't usually get posted there unless there is a really good sale or something is available for preorder.