Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te 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 ve » hieu va, hieu van
nang xa » lang xa, nang ma, mang xa
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((nang xa) or (nang x)) hoi. hieu ve cam duc ((va hanh) OR (va danh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (nang x)) hoi. hieu ve cam duc ((va hanh) OR (va danh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (nang x)) hoi. hieu ve cam duc ((va hanh) OR (va danh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (nang x)) hoi. hieu ve cam duc ((va hanh) OR (va danh)) vai cua tre*.