Perhaps you should try some spelling variations:
sach ty » sach tu, sach thu, xach tay
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
duc ban » duc tan, duc van, dua ban
anh hoi » anh noi, anh khoa, danh hoa
anh hoc » sinh hoc, benh hoc, hinh hoc
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
x hoi » xa hoi, o hoi, x ho

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

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