Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, mang xa
te sach » toc sach
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) y ((nang xa) or (nang ma)) hoi. hieu van cac luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y ((nang xa) OR (nang ma)) hoi. hieu van cac luc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) y ((nang xa) or (nang ma)) hoi. hieu van cac luc va hanh vi cua tre*.