Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
hieu lang » chieu sang, hieu quang, nhieu tang
trinh cua » tinh cua, trinh luat, trinh luan
dung cong » dung trong
doi hieu » doi chieu, doc hieu, doi hien
viec ban » viec lam, viec va, viec tai
dien va » dien hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - hanh ((trinh cua) OR (trinh quan)) dung cong ((viec ban) or (dien va)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh ((trinh cua) OR (trinh quan)) dung cong ((viec ban) OR (dien va)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - hanh ((trinh cua) OR (trinh quan)) dung cong ((viec ban) or (dien va)) cau".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh ((trinh cua) OR (trinh quan)) dung cong ((viec ban) or (dien va)) cau*.