17 books • 5 series
Book #2: Spitfire - the Anzacs
Book #3: American Spitfires
Book #5: From D-day to Victory
Book #6: Beaufighters, Corsairs
Book #7: Spitfires, Boomerangs, Captured Japanese and B-24s
Book #4: Seals No. 4
Book #7: Seals No. 7