- Author: John Hartley
- Language: English
- Year: 2003
- Author: John Hartley Indrek Ibrus Maarja Ojamaa
- Language: English
- Year: 2021
- Author: John Hartley
- Language: English
- Year: 2005
- Author: John Hartley
- Language: English
- Year: 2020
- Author: John Cresswell John Hartley
- Language: English, Esperanto
- Year: 1968
- Author: John Hartley Jason Potts
- Language: English
- Year: 2014
- Author: John Hartley Kelly McWilliam
- Language: English
- Year: 2009
- Author: John Hartley, Martin Montgomery, Ellie Rennie, Marc Brennan
- Language: English
- Year: 2002
- Author: John Hartley
- Language: English
- Year: 2012
- Author: John Hartley(auth.)
- Language: English
- Year: 2007