Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
phong cong » phong chong, thong cong, chong cong
hien xanh » hien hanh, hien nhanh, chieu xanh
hanh nang » anh nang, ganh nang, hanh mang
cao phong » cac phong, co phong, chau phong
hai toan » bai toan, hach toan, thai doan
hai tan » hai van, hai quan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien xanh) OR (chieu sach)) - hanh nang cao phong cong ((hai toan) OR (hai tan)) ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien xanh) or (chieu sach)) - hanh nang cao phong cong ((hai toan) OR (hai tan)) ban~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (chieu sach)) - hanh nang cao phong cong ((hai toan) OR (hai tan)) ban*.