Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tang » hanh trang, anh tang, hanh mang
cong tac » cong ty
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan tap
tang va » trang va, tang van, thang va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo hieu lang - hanh tang va nhung cong tac ((toan cau) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - hanh tang va nhung cong tac ((toan cau) OR (toan cao)).
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - hanh tang va nhung cong tac ((toan cau) or (toan cao))*.