Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
tu sach » thu sach, su sach, te sach
van cao » van bao, van hao, van cau
cua tre » cua te, cuu tre, cua triet
suc va » duc va, tuc va, luc va
va anh » van anh, va danh, va hanh
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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) or (tu sach)) ky nang x hoi. hieu ((van cao) OR (van dao)) suc va anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (tu sach)) ky nang x hoi. hieu ((van cao) OR (van dao)) suc va anh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (tu sach)) ky nang x hoi. hieu ((van cao) OR (van dao)) suc va anh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (tu sach)) ky nang x hoi. hieu ((van cao) OR (van dao)) suc va anh vi cua tre*.