Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
tran tuan » tran quang, tran thanh, tranh luan
tran xuan » tran quang, tran van
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, doc hieu
cong tac » cong ty
tac tran » tan tran, tac trai, tac tren
tran cau » tran chau, toan cau, ran 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 xuan)) dung cong tac tran cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu manh - thanh ((tran tuan) OR (tran xuan)) dung cong tac tran cau".
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - thanh ((tran tuan) OR (tran xuan)) dung cong tac tran cau*.