found:Work cat.: Panek, R. Yakovlev Yak-9U & P, 2006.
found:Wikipedia, 6 August 2009(the Yakovlev Yak-9 was a single-engine fighter aircraft used by the Soviet Union in World War II and after; it was the most numerous Soviet fighter of the war and remained in production from 1942 to 1948, with 16,769 built)
found:Virtual Aircraft Museum website, 6 August 2009(Yakovlev Yak-9; fighter)