Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, tran tuan
quang tuan » quang thanh, quan luan, quang cua
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
cac toan » cac khoan, hach toan, cac thanh
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: theo hieu lang - manh ((trung tuan) or (quang tuan)) dung trong cac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - manh ((trung tuan) OR (quang tuan)) dung trong cac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - manh ((trung tuan) or (quang tuan)) dung trong cac toan cau*.