Is there somewhere to see the latest tech tree? The only one I can find is the glossy diagram that came in the game box.

However, it seems that the new patch has made changes to the Tech Tree, including limiting certain units to later periods (unless I'm misreading the original - but I see no mention of Period in it). And I'm fairly sure that I used to be able to create Longbows early?

I can't find any details of this - can't see it in the patch Read Me, nor does there seem to be a button in the game itself to view the tree (seems an obvious feature to me).

Can someone please point me in the right direction?

Thanks in advance.