Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu manh » chieu xanh, hieu nganh, dieu hanh
trung cua » truong cua, trung tuan, trung cap
tang luan » dung luan
doc hieu » toc thieu, hoc thieu, hoc hien
cong san » cong tac
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu manh - hanh ((trung cua) OR (tang luan)) nhung cong san ((toan cau) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu manh - hanh ((trung cua) or (tang luan)) nhung cong san ((toan cau) OR (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: doc hieu manh - hanh ((trung cua) or (tang luan)) nhung cong san ((toan cau) OR (toan ban))*.