Perhaps you should try some spelling variations:
nang trong » nang truong, lang trong, mang trong
nhanh mang » nhanh lang, hanh mang, nhanh quang
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tung » thanh tung, manh tung, hanh dung
luan nang » luan van, van nang, luan san
trong tap » trong thap, tong tap, trong tan
tap quan » tac quan, hai quan
quan cau » quang cao, toan cau, quan ha

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: doc ((hieu sang) OR (hieu lang)) - ((hanh tung) OR (nhanh mang)) luan nang trong tap quan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu lang)) - ((hanh tung) or (nhanh mang)) luan nang trong tap quan cau~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu lang)) - ((hanh tung) or (nhanh mang)) luan nang trong tap quan cau*.