- Author: Steven S. Gubser, Frans Pretorius
- Language: English
- Year: 2017
I buchi neri
epub
- Author: Steven S. Gubser, Frans Pretorius
- Language: Italian
- Year: 2018
- Author: Steven S. Gubser & Frans Pretorius
- Language: Spanish
- Year: 2017
- Author: Steven S. Gubser & Frans Pretorius
- Language: English
- Year: 2017