- Author: Janusz Ledwoch Halina Trojca Waldemar Trojca
- Language: Polish
- Year: 1995
- Author: Janusz - Halina I Waldemar Trojca Ledwoch
- Language: English
- Year: 1995
- Author: Janusz Ledwoch
- Language: Polish
- Year: 1996
- Author: Janusz Ledwoch
- Language: Polish
- Year: 1997