Perhaps you should try some spelling variations:
dang xay » dang van, van xay
so sach » so sanh, bo sach, co sach
cam duc » cam xuc, cao duc, pham duc
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
lang ha » long ha
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((dang xay) or (lang ha)) hoi. hieu va cam duc ((va hanh) OR (va danh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((dang xay) OR (lang ha)) hoi. hieu va cam duc ((va hanh) OR (va danh)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((dang xay) or (lang ha)) hoi. hieu va cam duc ((va hanh) OR (va danh)) vai cua tre*".