Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Sino-Soviet Non-Aggression Pact:

"

The treaty also allowed the USSR to focus its attention more on the Western border where Nazi Germany was building up for what appeared to be war with the USSR especially after the Soviet-Japanese Neutrality Pact was signed. The pact contributed to the worsening relationship between China and Nazi Germany, which had already seen the end of German military assistance in China.