Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
chiet tach » chieu sach
hieu lang » chieu sang, nhieu tang, hieu van
hanh hang » thanh hang, hang hang, hanh han
nang cong » nang song, dang cong, bang cong
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
toan cau » toan cao, toan ban, toan tap
va nang » van nang, da nang, cam nang

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

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