Perhaps you should try some spelling variations:
thanh trung » thanh tung
phuong tran » huong tran, phuong trinh, phuong thao
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
cua thong » cua thuong, cua khong, cua tong
thong tan » thong than, thong tran, thong tin
hoc hieu » hoc thieu, hoc hien, doc hieu
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - thanh trung cua thong ((thong tan) or (phuong tran)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - thanh trung cua thong ((thong tan) OR (phuong tran)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - thanh trung cua thong ((thong tan) or (phuong tran)) toan cau*.