I finally managed to convince my lib friend to accept that he may be wrong about tibet (he thinks that the chinese settler colonised tibet), and that I should give him some sources for reading and for him to make up his mind.

However, I don't really know where to start in finding good quality sources that he will trust (he is very distrustful of Chinese sources). Does anybody know any good sources I can use? Our argument revolves around 2 main points

1. China did not conduct a genocide in tibet
2. Tibet was a feudal theocratic society before its liberation.

Much appreciated.