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
Britta von Buten Bremen
 
Erk von der Birkenallee
Olf vom Heidetal
Pascha vom Glockeneck