Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, nhung don
hieu sang » chieu sang, hieu lang, hieu quang
truong va » truong dai, truong cao, truong dao
hang cong » dang cong, hang nong, bang cong
doc hieu » toc thieu, hoc thieu, hoc hien
trong ca » trong cac, trong nha
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 sang - manh ((trong ca) OR (truong va)) ((nhung cong) OR (hang cong)) tinh toan cao~.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - manh ((trong ca) or (truong va)) ((nhung cong) or (hang cong)) tinh toan cao*.