Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
hieu lang » chieu sang, hieu quang, nhieu tang
trinh cua » tinh cua, trinh quan, trinh luan
dung cong » dung trong
tan toan » tan tran, tap toan, van toan
toan cau » toan cao, toan ban, toan tap
ho hieu » ho chieu, hoi hieu, nho hieu

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

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