Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
hoc thieu » hoc hien
dung dong » dung cong, vung dong, dung trong
dong tinh » dong kinh, dong tin, cong tinh
trinh va » trinh van, trinh vat, trinh ve
toan cao » toan ban, toan tap
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thieu) or (toc thieu)) sang - canh trinh va dung dong tinh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (toc thieu)) sang - canh trinh va dung dong tinh toan cao*.