https://doi.org/10.11588/ger.1921.2
https://doi.org/10.11588/ger.1921.1
https://doi.org/10.11588/ger.1920.3/6
https://doi.org/10.11588/ger.1920.1/2
https://doi.org/10.11588/ger.1919.5/6
https://doi.org/10.11588/ger.1919.3/4
https://doi.org/10.11588/ger.1919.2
https://doi.org/10.11588/ger.1919.1
https://doi.org/10.11588/ger.1918.5/6
https://doi.org/10.11588/ger.1918.3/4
https://doi.org/10.11588/ger.1918.2
https://doi.org/10.11588/ger.1918.1
https://doi.org/10.11588/ger.1917.6
https://doi.org/10.11588/ger.1917.5
https://doi.org/10.11588/ger.1917.4
https://doi.org/10.11588/ger.1917.3
https://doi.org/10.11588/ger.1917.2
https://doi.org/10.11588/ger.1917.1