Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
chinh cua » chinh ca, chinh sua, hinh cua
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, doc hieu
chinh va » chinh ta, chinh tai, hanh va
cong dan » cong san, cong tan, huong dan
toan cau » toan cao, toan tap, toan tai
toan ban » van ban

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 ((chinh cua) or (chinh va)) dung cong dan ((toan cau) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - hanh ((chinh cua) OR (chinh va)) dung cong dan ((toan cau) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - hanh ((chinh cua) or (chinh va)) dung cong dan ((toan cau) or (toan ban))*.