Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
cong thanh » dong thanh, cong trinh, truong thanh
hanh tran » hanh trang, thanh tran, hanh tram
tran van » luan van
van dung » van dong, xay dung, tin dung
cong tan » cong tac, cong san, cong ty
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 (thuat tach)) - hanh tran van dung ((cong tan) OR (cong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thuat tach)) - hanh tran van dung ((cong tan) OR (cong thanh)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) or (thuat tach)) - hanh tran van dung ((cong tan) OR (cong thanh)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) or (thuat tach)) - hanh tran van dung ((cong tan) OR (cong thanh)) toan cau*.