Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tran » hanh trang, thanh tran, hanh tram
nang cong » nang song, dang cong, bang cong
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
tran van » luan van
van nang » van quang, van ban, van dong
toan cau » toan cao, toan ban, toan tap

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 sach) or (hieu lang)) - hanh tran van nang cong manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - hanh tran van nang cong manh toan cau.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu lang)) - hanh tran van nang cong manh toan cau*.