Perhaps you should try some spelling variations:
truong toan » truong ton, trong toan, truong tan
thong huong » thong thuong, thong duong, thong thong
chieu sang » chieu sach, chieu xanh, hieu lang
trung toan » trung tuan, trung tran, trong toan
ho chieu » theo chieu, hoc thieu, doi chieu
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sang - thanh ((trung toan) OR (truong toan)) thong huong dan than cau~.
• Adding a wildcard symbol may retrieve word variants: ho chieu sang - thanh ((trung toan) or (truong toan)) thong huong dan than cau*.