Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doi chi, ho chieu, mot chieu
viet dung » viet hung, viet huong, viet trung
doc hieu » toc thieu, hoc thieu, hoc hien
vat dung » van dung, va dung, mat duong
cong san » cong tac
san phan » san pham, van phan, sat phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (doc hieu)) xanh - canh trinh ((vat dung) OR (viet dung)) cong san phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - canh trinh ((vat dung) OR (viet dung)) cong san phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (doc hieu)) xanh - canh trinh ((vat dung) OR (viet dung)) cong san phan tu".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) xanh - canh trinh ((vat dung) OR (viet dung)) cong san phan tu*.