Perhaps you should try some spelling variations:
tran thanh » ban thanh, van thanh, quan thanh
hieu manh » chieu xanh, hieu nganh, dieu hanh
tran tuan » tran xuan, tran quang, tranh luan
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, doc hieu
cong tac » cong ty
tran cau » tran chau, toan cau, tra cau
ran cau » van cau, ban cau, can cau

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 - thanh ((tran tuan) or (tran thanh)) dung cong tac ((tran cau) OR (ran cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu manh - thanh ((tran tuan) OR (tran thanh)) dung cong tac ((tran cau) OR (ran cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu manh - thanh ((tran tuan) or (tran thanh)) dung cong tac ((tran cau) OR (ran cau))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - thanh ((tran tuan) or (tran thanh)) dung cong tac ((tran cau) OR (ran cau))*.