Perhaps you should try some spelling variations:
thiet tach » chiet tach, thuat tach
thien hach » thien thanh, hien hanh
hanh tran » hanh trang, thanh tran, hanh tram
trong dan » trong dang, trong san, trong tan
tran van » luan van
van dung » van dong, xay dung, tin dung
dan toan » van toan, dan than, manh toan
toan cau » 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: hoc ((thiet tach) or (thien hach)) - hanh tran van dung trong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thien hach)) - hanh tran van dung trong dan toan cau*.