- Author: Diễn đàn MathScope
- Language: Vietnamese
- Year: 2012
- Author: Diễn đàn MathScope
- Language: Vietnamese
- Year: 2010
- Author: Diễn đàn MathScope
- Language: Vietnamese
- Year: 2012
- Author: Diễn đàn MathScope
- Language: Vietnamese
- Year: 2011
- Author: Phạm Tiến Kha Diễn đàn MathScope
- Language: Vietnamese
- Year: 2013