Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
chu tre » cho tre, chu tri, cuu tre
ve cac » va cac, vien cac
cac do » cac don, cac doi, cac du
vi chu » va chu, ve chu, viet chu
do va » do van, so va

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 tu ((nang xa) or (nang x)) hoi. hieu ve cac do va hanh vi chu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nang xa) OR (nang x)) hoi. hieu ve cac do va hanh vi chu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nang xa) or (nang x)) hoi. hieu ve cac do va hanh vi chu tre*.