Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh trinh » canh tranh, hanh chinh
cong dang » cong dong, cong dan, cong dung
hoc hieu » hoc thieu, hoc hien, doc hieu
dang van » hoang van, hang va
va hang » van hang, va nang, va hanh
va lang » va nang, hoa lang

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 quang - hanh trinh ((va hang) or (va lang)) cong dang van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quang - hanh trinh ((va hang) OR (va lang)) cong dang van ban*.