- Author: Stiftung Warentest
- Language: German
- Year: 2021
- Author: Stiftung Warentest
- Language: German
- Year: 2021
- Author: Stiftung Warentest
- Language: German
- Year: 2021
- Author: Stiftung Warentest, Hess Thomas
- Language: German
- Year: 2019
- Author: Stiftung Warentest, Siepe Werner
- Language: German
- Year: 2018
- Author: Stiftung Warentest, Lange Elisabeth
- Language: German
- Year: 2011
- Author: Stiftung Warentest
- Language: German
- Year: 2013
- Author: Stiftung Warentest
- Language: German
- Year: 2016
- Author: Stiftung Warentest Finanztest 04-2014
- Language: German
- Year: 2014
- Author: Stiftung Warentest Finanztest 03-2014
- Language: German
- Year: 2014