Looking for information on finnish propaganda from world war two...?

The Russians were invading too, you just don't here about it. Back when in 1937 through 1939. The Russians invaded Finland as part of a secret pact signed between Russia and Nazi Germany. The Russians invaded Finland and since Staling purged most of their army staff. They almost got beat by the Fins. It took a lot of losses and eventually the Russians won. But the Russian Army was totally humiliated that the Finnish army could decimate that much Russian Firepower. I cannot prove it. But it has been said the Hitler did this to see just how strong the Russian were and that there lack of strentgh was one reason why he attacked before his generals said they should.