Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, thien anh, thien danh
hieu manh » chieu xanh, hieu nganh, dieu hanh
trung dam » trung tam, trong dam, trung nam
trung dai » truong dai, truong dao, trung tam
trong san » trong cac, cong san, dong san
san toan » van toan, dan toan, manh toan
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 ((thieu xanh) OR (hieu manh)) - hanh ((trung dam) or (trung dai)) dung trong san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (hieu manh)) - hanh ((trung dam) OR (trung dai)) dung trong san toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (hieu manh)) - hanh ((trung dam) or (trung dai)) dung trong san toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (hieu manh)) - hanh ((trung dam) or (trung dai)) dung trong san toan cao*.