Perhaps you should try some spelling variations:
quan thanh » ban thanh, van thanh
hieu manh » chieu xanh, hieu nganh, dieu hanh
tran tuan » tran xuan, tran quang, tran thanh
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
tran cau » tran chau, ran cau, tra cau
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: doc hieu manh - thanh ((tran tuan) or (quan thanh)) dung cong ty ((tran cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu manh - thanh ((tran tuan) OR (quan thanh)) dung cong ty ((tran cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu manh - thanh ((tran tuan) or (quan thanh)) dung cong ty ((tran cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: doc hieu manh - thanh ((tran tuan) or (quan thanh)) dung cong ty ((tran cau) OR (toan cau))*.