Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hiem ngan » kim ngan, viem gan
nang cong » nang song, dang cong, bang cong
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
trang va » hang va
tran van » luan van
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: hoc ((chieu sach) or (hiem ngan)) - hanh ((trang va) or (tran van)) nang cong manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (hiem ngan)) - hanh ((trang va) OR (tran van)) nang cong manh toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (hiem ngan)) - hanh ((trang va) or (tran van)) nang cong manh toan cau*.