Perhaps you should try some spelling variations:
ninh viet » sinh vien, anh viet
viet cua » viec cua, viet ca, viet qua
van ninh » van minh, van dinh, van binh
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
tu chao » tu cham, tu cao, tu thao
tu chat » tu phat, tu cham, du chat
xu van » tu van, vu van, su van
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cac) or (so sach)) ky nang x hoi. khien ((tu chao) OR (tu chat)) xu van ninh viet cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (so sach)) ky nang x hoi. khien ((tu chao) OR (tu chat)) xu van ninh viet cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (so sach)) ky nang x hoi. khien ((tu chao) OR (tu chat)) xu van ninh viet cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cac) or (so sach)) ky nang x hoi. khien ((tu chao) OR (tu chat)) xu van ninh viet cua tre*.