Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
trinh ven » trinh van, trinh den, tinh ven
trinh ve » trinh he, trinh va, trinh vi
tap toan » tap doan, tap quan
bai toan » bai 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 xanh - hanh ((trinh ve) or (trinh ven)) nhung cong ((tap toan) or (bai toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu xanh - hanh ((trinh ve) OR (trinh ven)) nhung cong ((tap toan) OR (bai toan)) cao.
• Adding a wildcard symbol may retrieve word variants: theo chieu xanh - hanh ((trinh ve) or (trinh ven)) nhung cong ((tap toan) or (bai toan)) cao*.