Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
trung cap » truong cao, trung tam
san thang » van thang, san thanh, cang thang
san chang » ban hang, dan chan, van khang
hoc hieu » hoc thieu, hoc hien, doc hieu
thong tu » phong tuc, thong tin, thong ke

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - hanh ((thong tu) or (trung cap)) thong cong ((san thang) OR (san chang)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - hanh ((thong tu) OR (trung cap)) thong cong ((san thang) OR (san chang)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - hanh ((thong tu) or (trung cap)) thong cong ((san thang) OR (san chang)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh ((thong tu) or (trung cap)) thong cong ((san thang) OR (san chang)) cau*.