Perhaps you should try some spelling variations:
trong dang » truong dang, trong dan, trong dong
hieu xanh » chieu xanh, hieu manh, hieu nganh
huong cua » dung cua
tang luan » dung luan
dang toan » dang tran, dan toan, dung toan
doc hieu » toc thieu, hoc thieu, hoc hien
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu xanh - hanh ((huong cua) or (tang luan)) dung trong dang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh ((huong cua) OR (tang luan)) dung trong dang toan ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((huong cua) or (tang luan)) dung trong dang toan ban*.