Perhaps you should try some spelling variations:
hanh trung » thanh trung, hanh trang, manh trung
nhieu tang » chieu sang, nhiet nang
hieu lang » chieu sang, hieu quang, hieu van
trung cua » truong cua, trung tuan, trung cap
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
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: hoc ((nhieu tang) OR (hieu lang)) - hanh trung cua ((hang cong) OR (dang cong)) tac toan cau~.
• Adding a wildcard symbol may retrieve word variants: hoc ((nhieu tang) or (hieu lang)) - hanh trung cua ((hang cong) or (dang cong)) tac toan cau*.