"But Wikipedia itself is actually unreliable and biased on most of the historical or political articles." --AC
Anyone expecting to find a single reliable source for contentious issues such as history or politics, especially the nearer they are in time, is incredibly naive. One of the best lessons from W is "do not rely on a single source"
Remember Alexander Pope's words (Essay on Criticism, I think)
A little learning is a dangerous thing;
drink deep, or taste not the Pierian spring:
there, shallow draughts intoxicate the brain,
and drinking largely sobers us again.