- Author: Crockford Douglas
- Language: English
- Year: 2008
- Author: Crockford Douglas
- Language: English
- Year: 2008
- Author: Crockford Douglas
- Language: English
- Year: 2008
- Author: Crockford Douglas
- Language: English
- Year: 2008
- Author: Crockford Douglas, Yan xue kun, Zhao ze xin
- Language: Chinese, English
- Year: 2009