Perhaps you should try some spelling variations:
ninh viet » sinh vien, anh viet
hoc sach » hoc sinh, hoc cac, hoc anh
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty nang xa hoi. hieu ((ve cam) or (ve cac)) xuc va ((ninh viet) or (chinh tri)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty nang xa hoi. hieu ((ve cam) OR (ve cac)) xuc va ((ninh viet) OR (chinh tri)) cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ty nang xa hoi. hieu ((ve cam) or (ve cac)) xuc va ((ninh viet) or (chinh tri)) cua tre*.