These are a really nice looking set of papercraft tanks from Sega, after a bit of sleuthing I am pretty confident that it comes from the Dreamcast game; Advanced Daisenryaku 2001 and to be honest, the very little I do know about this game is from the fountain of knowledge itself, Wikipedia:
Advanced Daisenryaku 2001 is a follow up to SystemSoft Alpha's Advanced Daisenryaku: Europe no Arashi. Both games run on Sega's Dreamcast system. Advanced Daisenryaku 2001 fixed some bugs and moderately improved the graphics of Europe no Arashi and as such it is less of a sequel and more of a fix.
Grab the papercraft here. (Sadly I can only find the link to one of awesome looking tanks :( If anybody has any luck locating the rest on the site let me know!)