Perhaps you should try some spelling variations:
doi chieu » doi chi, ho chieu, mot chieu
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
vat dung » van dung, va dung, viet dung
van toan » van tan, van thanh, manh toan
van tuan » van quan, van ban, anh tuan

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 - hanh sinh vat dung cong ((van toan) or (van tuan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - hanh sinh vat dung cong ((van toan) OR (van tuan)) ban.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) xanh - hanh sinh vat dung cong ((van toan) or (van tuan)) ban*.