- Author: Niels Henrik Gregersen Bo Holm Ted Peters Peter Widmann
- Language: English
- Year: 2004
- Author: Niels Henrik Gregersen
- Language: English
- Year: 2015
- Author: Niels Henrik Gregersen
- Language: Romanian
- Year: 2007
- Author: Paul Davies & Niels Henrik Gregersen
- Language: English
- Year: 2010
- Author: Paul Davies Niels Henrik Gregersen
- Language: English
- Year: 2010
- Author: Paul Davies Niels Henrik Gregersen
- Language: English
- Year: 2010
- Author: Paul Davies (editor) Niels Henrik Gregersen (editor)
- Language: English
- Year: 2010
- Author: Niels Henrik Gregersen
- Language: English
- Year: 2002
- Author: Niels Henrik Gregersen
- Language: English
- Year: 2002