Perhaps you should try some spelling variations:
thang long » thanh cong
hieu sang » chieu sang, hieu lang, hieu quang
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
tinh luan » trinh luan, binh luan, minh luan
dang cong » dung cong
thanh phi » thanh pho, thanh phan, thanh pham
doc hieu » toc thieu, hoc thieu, hoc hien
phi van » phi san, thi van, phi va

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 - hanh tinh luan ((dang cong) or (thang long)) thanh phi van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hanh tinh luan ((dang cong) OR (thang long)) thanh phi van.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - hanh tinh luan ((dang cong) or (thang long)) thanh phi van*.