This book is banned in Germany
The Myth of the 20th Century counts as the second most important book after Mein Kampf for the understanding of National-socialism, the ideology that inspired Hitler, and the path that led to World War 2.

It is a common practice of totalitarian dictatorships such as Nazi Germany and the Soviet Union to ban books that authorities did not approve of.

Unfortunately this also seems to be the case in modern day Germany, a country that claims to respect freedom of thought.

But see for yourself. The Myth of the 20th Century (ISBN 1467987581)
 is freely available on Amazon in these countries:

But then check the german Amazon:

What are German authorities trying to hide from their people?