Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
thien hach » thien thanh, hien hanh
hien sach » dien sach, kien sach, chieu sach
trong xay » thong xay, trong cac, trong ca
cong tap » cuong tap, cong tan, tong tap
cong tac » 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 ((hien sach) or (thien hach)) - thanh trong xay dung ((cong tap) OR (cong tac)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sach) OR (thien hach)) - thanh trong xay dung ((cong tap) OR (cong tac)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sach) or (thien hach)) - thanh trong xay dung ((cong tap) OR (cong tac)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sach) or (thien hach)) - thanh trong xay dung ((cong tap) OR (cong tac)) toan cau*.