Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hanh trinh » canh tranh, hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
trinh cua » tinh cua, trinh luat, trinh quan
cua thong » cua thuong, cua khong, cua tong
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi ((hieu lang) or (hieu qua)) - hanh trinh cua thong cong dan than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (hieu qua)) - hanh trinh cua thong cong dan than cao.
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu qua)) - hanh trinh cua thong cong dan than cao*.