This bloodline traces back the sires to what have been identified as the 3 foundation lines of the German Shepherd. Mutz von der Pelztierfame, Quanto von der Wienerau and Canto von der Wienerau.
The bloodlines may not be complete either because no information is available or the data has not yet been completed. 

Sire Bloodlines for
Engy von der Burg Botzlar
 
Dok vom Friedlichenheim
Alexis von der Grone