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 Military history of Poland during World War II:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

"

Polish intelligence supplied valuable intelligence to the Allies; 48% of all reports received by the British secret services from continental Europe in between 1939 and 1945 came from Polish sources.[1] The total number of those reports is estimated at 80,000, and 85% of them were deemed high or better quality.[2] Despite Poland becoming occupied, the Polish intelligence network not only survived but grew rapidly, and near the end of the war had over 1,600 registered agents[1] (Another estimate gave about 3,500[citation needed]).