Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hoi hieu » hoi phieu, hoi tieu, moi hieu
vat dung » van dung, viet dung, mat duong
quan dau » quan cau, qua dau, quan dac
ho hieu » ho chieu, nho hieu, co hieu
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: ((ho hieu) or (hoi hieu)) lang - hanh tinh ((va dung) OR (vat dung)) cong trinh quan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho hieu) OR (hoi hieu)) lang - hanh tinh ((va dung) OR (vat dung)) cong trinh quan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho hieu) or (hoi hieu)) lang - hanh tinh ((va dung) OR (vat dung)) cong trinh quan dau".
• Adding a wildcard symbol may retrieve word variants: ((ho hieu) or (hoi hieu)) lang - hanh tinh ((va dung) OR (vat dung)) cong trinh quan dau*.