Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van lam » van nam
van cam » van nam, van cau, van dam
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
bao va » bao ve, tao va, ban va
loc va » hoc va, luc va
o lang » hoa lang, hoi lang
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: thuoc sach o lang xa hoi. hieu ((van cam) or (van lam)) ((bao va) or (loc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach o lang xa hoi. hieu ((van cam) OR (van lam)) ((bao va) OR (loc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach o lang xa hoi. hieu ((van cam) or (van lam)) ((bao va) or (loc va)) hanh vi cua tre*.