Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, mot chieu
hang tai » hang va, dung tai
cong tac » cong ty
tac thai » toc thai, rac thai, sac thai
thai cao » tai cao, thoai cac, thuat cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) OR (doi chieu)) xanh - hanh ((nang cao) or (hang tai)) dung cong tac thai cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) xanh - hanh ((nang cao) OR (hang tai)) dung cong tac thai cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) xanh - hanh ((nang cao) or (hang tai)) dung cong tac thai cao*".