Your article has a good point about the separation of the GSD breed between show dogs and working dogs.
It falls a little short on the working blood line.
The two more famous working blood lines you often see used by military and police all over the world do come from the former DDR (Eastern Germany) and from the Czech Republic.
They are not bred with other dog breeds. Since they were however bred in a closed governmental system they have developed characteristics different from the non working show blood lines.
Yes these blood lines have more in common with the original breed from the mid to late 1800s.
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