- Author: Axel Ritter
- Language: German
- Year: 2006
- Author: Axel Ritter
- Language: English
- Year: 2006
- Author: Lucius Burckhardt (editor), Markus Ritter (editor), Martin Schmitz (editor)
- Language: English
- Year: 2015
- Author: Archibald R.M. Ritter, Ted A. Henken
- Language: English
- Year: 2022
- Author: Luke Ritter
- Language: English
- Year: 2020
- Author: Gerhard Ritter
- Language: English
- Year: 2023
- Author: Yvonne Franke (editor), Kati Mozygemba (editor), Kathleen Pöge (editor), Bettina Ritter (editor), Dagmar Venohr (editor)
- Language: German
- Year: 2014
- Author: Nadine M. Schöneck (editor), Sabine Ritter (editor)
- Language: German
- Year: 2018
