Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
thanh than » thanh thanh, thanh thang, thanh toan
doi chieu » doc hieu, doi chi, mot chieu
anh quang » anh xquang, anh quan, nhanh quang
ho chieu » theo chieu, hoc thieu, mot chieu
van dung » van dong, xay dung, tin dung
than cau » toan cau, phan cau, than cap
va dung » va duong, vat dung, 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 chieu) or (doi chieu)) xanh - anh quang ((va dung) OR (van dung)) cong thanh than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) xanh - anh quang ((va dung) OR (van dung)) cong thanh than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (doi chieu)) xanh - anh quang ((va dung) OR (van dung)) cong thanh than cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chieu)) xanh - anh quang ((va dung) OR (van dung)) cong thanh than cau*.