Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dieu cua » dieu tra
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
va han » va phan, van han, va hang

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 tu nang xa hoi. hieu va cau truc ((va han) or (va hanh)) dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach tu nang xa hoi. hieu va cau truc ((va han) OR (va hanh)) dieu cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach tu nang xa hoi. hieu va cau truc ((va han) or (va hanh)) dieu cua tre*.