Perhaps you should try some spelling variations:
hieu tinh » chieu tinh, lieu tinh, kieu tinh
trong dan » trong dang, trong san, trong tan
doc hieu » toc thieu, hoc thieu, hoc hien
van dung » van dong, xay dung, tin dung
va duong » van duong, va tuong, va huong
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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 tinh - canh tranh ((van dung) or (va duong)) trong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - canh tranh ((van dung) OR (va duong)) trong dan toan cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - canh tranh ((van dung) or (va duong)) trong dan toan cao*.