German invasion of Poland

30 years ago I saw an inspiring photo–on the right side of the photo, stretching into the distance, are Polish troops lined up on horseback. Advancing across the valley towards them is a Panzer unit, deployed. I have recently been searching for this photo (fruitlessly) for a talk that I am giving. Any leads?

ghotai@hotmail.com

That sounds more like a piece of German propaganda, meant to show the Polish army in a backward light…