How do I tell anti-socialist propaganda?

For example, I just found these books in my dads library, and they sound very anti-socialist biased and inciting.

1. Mao. (2005) - Jung Chang, Jon Halliday

the blurb states (transation from german):

It was not the well-being of his people that Mao Zedong, the Great Chairman of the People's Republic of China, cared about. Nor was it communist ideology, although he sought its worldwide victory. The sole motive behind Mao's actions was, at all times, his absolute will to power. Whether on a personal, national, or international level, his hunger for power was boundless.

Mao Zedong achieved not all, but many of his goals, and China paid a heavy price: with the lives of 70 million people

- In my opinion, this sound already very biased and, from what I've heard, exaggerated and put completely out of context

In several Stalin and Lenin biographies my dad possesses, they're often called "tyranny" and "dictators",…

When I research the authors, they always seem like valid people. They're well known historians, they're authors with many books, they studies (for example) the soviet union,…

please help!