Where can you buy shonen jump online?

I really want to find Obelisk the Tormenter and Winged Dragon of Ra god cards (legal version) with the magazines. I don't know where to find and buy issue 37 and 45. I checked all yugioh stores and i couldn't find a single one of those god cards except for the fake ones until one of the storekeepers told me that I could find them in Shonen Jump magazine issue 37 and 45. Help!