Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
nhanh lang » nhanh quang, nhanh thang, nhan dang
cong vang » cong lang, cong quang, cong ngang
cong van » cong san, song van, cong tan
lang va » lang van, hang va, lang ha
va hang » van hang, va nang, va lang
tao cao » bao cao, toan cao

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)) - nhanh lang va hang ((cong van) OR (cong vang)) tao cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chieu sang)) - nhanh lang va hang ((cong van) OR (cong vang)) tao cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (chieu sang)) - nhanh lang va hang ((cong van) OR (cong vang)) tao cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chieu sang)) - nhanh lang va hang ((cong van) OR (cong vang)) tao cao*.