Michael has written a fascinating history of Fritz Gockerell. He has kindly provided expert information on Gockerell along with several images.
German Motorcycles of the 1920s - Fritz Gockerell, Megola, Pax...
Fritz Gockerell: Biografie eines Motorenkonstrukteurs
Verlag: Schick, Michael; Auflage: 1 (1. Februar 2017)
Sprache: Deutsch
ISBN-10: 3000553150
ISBN-13: 978-3000553158
Available from reputable booksellers, and also from Amazon.
Another of his books covers the Steiger automobile.
For Gockerell and the Megola visit megola.de