Perhaps you should try some spelling variations:
truong long » trong long, trung long, truong dong
truong cong » trong cong, truong dong, truong chung
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
tranh cua » doanh cua, manh cua
bai toan » bai tap
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: theo chieu sach - canh tranh cua ((truong cong) or (truong long)) bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - canh tranh cua ((truong cong) OR (truong long)) bai toan cao.
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - canh tranh cua ((truong cong) or (truong long)) bai toan cao*.