Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
hanh tang » hanh trang, anh tang, hanh mang
dung cong » dung trong
cong manh » cong danh, duong manh, cong thanh
tang vat » tang van, dang vat, bang vat
vat dung » van dung, va dung, viet dung
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban

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) or (hieu quang)) - hanh tang vat dung cong manh ((toan cau) OR (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (hieu quang)) - hanh tang vat dung cong manh ((toan cau) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi ((hieu lang) or (hieu quang)) - hanh tang vat dung cong manh ((toan cau) OR (toan tap))".
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu quang)) - hanh tang vat dung cong manh ((toan cau) OR (toan tap))*.