Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
trinh san » trinh quan, trinh toan, trinh luan
trinh han » trinh quan
hoi hieu » hoi phieu, hoi tieu, moi hieu
vat dung » van dung, viet dung, mat duong
va dung » van dung, va duong, va ung

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - hanh tinh ((va dung) OR (vat dung)) cong ((trinh san) or (trinh han)) dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - hanh tinh ((va dung) OR (vat dung)) cong ((trinh san) OR (trinh han)) dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - hanh tinh ((va dung) OR (vat dung)) cong ((trinh san) or (trinh han)) dau".
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - hanh tinh ((va dung) OR (vat dung)) cong ((trinh san) or (trinh han)) dau*.