Perhaps you should try some spelling variations:
thanh tung » thanh cong
hieu sang » chieu sang, hieu lang, hieu quang
doc hieu » toc thieu, hoc thieu, hoc hien
vat dung » van dung, viet dung, mat duong
cong ban » cong bang, cong san, cong tan
ban phan » ban phap, van phan, ban than
phan cau » phan dau, phan cac, phan tu
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: doc hieu sang - ((thanh trung) or (thanh tung)) ((va dung) OR (vat dung)) cong ban phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - ((thanh trung) OR (thanh tung)) ((va dung) OR (vat dung)) cong ban phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sang - ((thanh trung) or (thanh tung)) ((va dung) OR (vat dung)) cong ban phan cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - ((thanh trung) or (thanh tung)) ((va dung) OR (vat dung)) cong ban phan cau*.