- Author: Tullio Levi-Civita
- Language: English
- Year: 1927
- Author: Konrad Knopp
- Language: English
- Year: 1944
- Author: Levi-Civita T.
- Language: English
- Year: 2005
- Author: Vito Volterra
- Language: English
- Year: 1930
- Author: E. Schrodinger
- Language: English
- Year: 1929
- Author: H. W Turnbull
- Language: English
- Year: 1945
- Author: Peter Paul Ewald
- Language: English
- Year: 1932
- Author: Tullio Levi-Civita
- Language: English
- Year: 1927