Perhaps you should try some spelling variations:
nhanh dong » hanh dong, nhanh chong, anh dong
dong thuan » don thuan, dong chuan, dong thuong
hieu sang » chieu sang, hieu lang, hieu quang
cong cong » cong dong, trong cong, dung cong
tong cong » trong cong, dung cong, dang cong
doc hieu » toc thieu, hoc thieu, hoc hien
tan van » tran van, tang van, luan van

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 - nhanh dong thuan ((cong cong) or (tong cong)) tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - nhanh dong thuan ((cong cong) OR (tong cong)) tan van ban*.