Perhaps you should try some spelling variations:
hieu sang » chieu sang, hieu lang, hieu quang
cong hoat » cong hoa, rong hoat, cong hoan
dong cong » duong cong, dung cong, dang cong
doc hieu » toc thieu, hoc thieu, hoc hien
cong tac » cong ty
tac tren » rac tren, tai tren, tap tren
tren ban » trien ban, tren san, trong ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - thanh cong hoat dong cong tac tren ban~.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - thanh cong hoat dong cong tac tren ban*.