Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
loc va » hoc va, luc 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 ky ((nang x) or (nang cao)) hoi. hieu ve chat ((xuc va) or (loc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (nang cao)) hoi. hieu ve chat ((xuc va) OR (loc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (nang cao)) hoi. hieu ve chat ((xuc va) or (loc va)) hanh vi cua tre*.