- Author: August Ludwig Busch
- Language: German
- Year: 1868
- Author: Emil Lehmann
- Language: German
- Year: 1861
- Author: August Ludwig von Rochau
- Language: German
- Year: 1870
- Author: Theodor Barth
- Language: German
- Year: 1907
Metaphysik
pdf
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- Language: German
- Year: 1890
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- Language: German
- Year: 1862
- Author: Ernst Haeckel
- Language: German
- Year: 1862