Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh va
te sach » toc sach
vai cua » dai cua, hai cua, lai cua
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
van hoi » van hoa, van hoe, van loi
van hoc » van hoa
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
lo van » vo van, so van, do van

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky dang ((van hoi) OR (van hoc)). hieu va cam ((lo van) or (le van)) dinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ((van hoi) OR (van hoc)). hieu va cam ((lo van) OR (le van)) dinh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang ((van hoi) OR (van hoc)). hieu va cam ((lo van) or (le van)) dinh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang ((van hoi) OR (van hoc)). hieu va cam ((lo van) or (le van)) dinh vai cua tre*.