- Author: Astrid Sigel (editor), Helmut Sigel (editor), Roland K.O. Sigel (editor)
- Language: English
- Year: 2015
- Author: Astrid Sigel (editor), Helmut Sigel (editor), Roland K.O. Sigel (editor)
- Language: English
- Year: 2015
- Author: Astrid Sigel (editor), Helmut Sigel (editor), Roland K.O. Sigel (editor)
- Language: English
- Year: 2015
- Author: Astrid Sigel (editor), Helmut Sigel (editor), Roland K.O. Sigel (editor)
- Language: English
- Year: 2015
- Author: Astrid Sigel (editor), Helmut Sigel (editor), Roland K.O. Sigel (editor)
- Language: English
- Year: 2015