Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, cham soc, pham duy
van cham » van chat, van tham, va cham
sang tao » hang tai
va hanh » van hanh, va thanh, va danh
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
sang ma » tang ma, nang ma, mang may
cua tre » cua te, cuu tre, cua triet
ca dan » cac dan, ca dao

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 ty ((sang ma) or (sang tao)) hoi. hieu van cham duc ((va hanh) or (ca dan)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((sang ma) OR (sang tao)) hoi. hieu van cham duc ((va hanh) OR (ca dan)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((sang ma) or (sang tao)) hoi. hieu van cham duc ((va hanh) or (ca dan)) dai cua tre*.