Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
trung cap » truong cao, trung tam
thanh cau » thanh chau, thanh mau, nhanh cau
hoc hieu » hoc thieu, hoc hien, doc hieu
thong tu » phong tuc, thong tin, thong ke
cong van » cong vang, cong san, cong tan
song van » hoang van, trong van, duong van

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 van) OR (song van)) thanh 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 van) OR (song van)) thanh 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 van) OR (song van)) thanh cau".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh ((thong tu) or (trung cap)) thong ((cong van) OR (song van)) thanh cau*.