Big History Project official website International Big History Association official website David Christian's TED Talk Timelines from David Christian's TED Talk So Bill Gates Has This Idea for a History Class ...
Truy cập 26 tháng 9 năm 2014.  Big History Project official website International Big History Association official website David Christian's TED Talk Timelines from David Christian's TED Talk So Bill Gates Has This Idea for a History Class...