Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
canh trinh » canh tranh, hanh trinh, canh tinh
nhung song » nhung cong, nhung bong, nhung chong
luan phan » luan van, luan hoan
trinh va » trinh van, trinh vat, trinh ve
van phan » van phong, van thanh, van ban

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 (chieu sang)) - canh trinh va nhung song ((van phan) or (luan phan)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chieu sang)) - canh trinh va nhung song ((van phan) OR (luan phan)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) OR (chieu sang)) - canh trinh va nhung song ((van phan) or (luan phan)) tu".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) OR (chieu sang)) - canh trinh va nhung song ((van phan) or (luan phan)) tu*.