Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
chieu sang » chieu sach, chieu xanh, hieu lang
hang cong » dang cong, hang nong, bang cong
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: theo ((hieu nganh) OR (chieu sang)) - hanh ((tang cua) OR (mang cua)) hang cong tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu nganh) or (chieu sang)) - hanh ((tang cua) OR (mang cua)) hang cong tac toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu nganh) or (chieu sang)) - hanh ((tang cua) OR (mang cua)) hang cong tac toan cau*.