Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » thong cong, hang cong, nhung don
hien xanh » hien hanh, hien nhanh, chieu xanh
dung cong » dung trong
tranh va » tranh van, trang va, trinh va
dan than » dan chan, ban than, van than
than tu » thanh tu, thang tu, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien xanh) or (chieu sach)) - hanh tranh va ((nhung cong) or (dung cong)) dan than tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien xanh) OR (chieu sach)) - hanh tranh va ((nhung cong) OR (dung cong)) dan than tu.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (chieu sach)) - hanh tranh va ((nhung cong) or (dung cong)) dan than tu*.