Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
thong cong » trong cong, tong cong, thong thong
vang thanh » van thanh, dang thanh, tang thanh
trung cao » truong cao, trung cap, trung ca
cong vang » cong lang, cong quang, cong ngang
thanh cau » thanh chau, thanh mau, nhanh cau
trung co » trung bo, trong co, truong cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - thanh ((trung cao) OR (trung co)) thong cong vang thanh cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - thanh ((trung cao) OR (trung co)) thong cong vang thanh cau".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - thanh ((trung cao) OR (trung co)) thong cong vang thanh cau*.