Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
trinh thuat » trinh luat, trinh thuc, trinh chat
dung thuong » dung trong, hang thuong, cong thuong
chieu sang » chieu sach, hieu lang, nhieu tang
chieu xanh » chieu sach, chieu tinh, hieu manh
thuong san » thuong han, thuong lan, thong san
san van » tan van, luan van, tran van
van cau » van dau, van hau, van chat

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 sang) or (chieu xanh)) - hanh ((trinh thuat) OR (trinh thiet)) dung thuong san van cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (chieu xanh)) - hanh ((trinh thuat) OR (trinh thiet)) dung thuong san van cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (chieu xanh)) - hanh ((trinh thuat) OR (trinh thiet)) dung thuong san van cau".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (chieu xanh)) - hanh ((trinh thuat) OR (trinh thiet)) dung thuong san van cau*.