Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
dung cong » dung trong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
luan » quan, lan

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 (thuat tach)) - hanh ((tran van) OR (luan van)) dung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thuat tach)) - hanh ((tran van) OR (luan van)) dung cong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) or (thuat tach)) - hanh ((tran van) OR (luan van)) dung cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) or (thuat tach)) - hanh ((tran van) OR (luan van)) dung cong dan toan cau*.