Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu xanh » chieu xanh, hieu manh, hieu nganh
trung cua » truong cua, trung tuan, trung cap
doc hieu » toc thieu, hoc thieu, hoc hien
tang cua » hang cua, tang luan, thong cua
mang cua » manh cua, dung cua, ban cua
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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 xanh - hanh ((trung cua) OR (((tang cua) OR (mang cua)))) nhung cong tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh ((trung cua) or (((tang cua) OR (mang cua)))) nhung cong tac toan cau~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((trung cua) or (((tang cua) OR (mang cua)))) nhung cong tac toan cau*.