Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doc hieu, doi chi, ho chieu
vat nhung » vap nhung, vai nhung, ve nhung
cong dan » cong san, cong tan, huong dan
dan phan » doan phan, dan chan, van 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 (theo chieu)) xanh - canh trinh ((vat nhung) OR (va nhung)) cong dan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (theo chieu)) xanh - canh trinh ((vat nhung) OR (va nhung)) cong dan phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (theo chieu)) xanh - canh trinh ((vat nhung) OR (va nhung)) cong dan phan tu".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (theo chieu)) xanh - canh trinh ((vat nhung) OR (va nhung)) cong dan phan tu*.