Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thanh tran » thanh trang, thanh toan, thanh tra
dung tuong » dung thuong, dung truong, dung trong
hieu sang » chieu sang, hieu lang, nhieu tang
tuan dung » tuan duong, tran dung, tan dung
tuong dan » huong dan, tung dan, xuong dan
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) OR (hieu quang)) - ((thanh tran) or (thanh san)) tuan dung tuong dan chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - ((thanh tran) OR (thanh san)) tuan dung tuong dan chan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu quang)) - ((thanh tran) or (thanh san)) tuan dung tuong dan chan cau*".