Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
hieu manh » chieu xanh, hieu nganh, dieu hanh
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cao » toan ban, toan tap
hang ca » nang cao, hang tai, hang dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu manh) or (thien thanh)) - anh ((hang ca) OR (hang va)) nhung cong san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (thien thanh)) - anh ((hang ca) OR (hang va)) nhung cong san toan cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (thien thanh)) - anh ((hang ca) OR (hang va)) nhung cong san toan cao*".