Perhaps you should try some spelling variations:
thanh trung » thanh tung
trung thanh » truong thanh
thanh thong » thanh thuong, thanh hong, thanh thang
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
van chan » van chat, van phan, van nhan
dan chan » dan gian, dan ca, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sang) or (chieu sang)) - thanh trung thanh thong thong ((van chan) OR (dan chan)) cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sang)) - thanh trung thanh thong thong ((van chan) OR (dan chan)) cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (chieu sang)) - thanh trung thanh thong thong ((van chan) OR (dan chan)) cac".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sang)) - thanh trung thanh thong thong ((van chan) OR (dan chan)) cac*.