Perhaps you should try some spelling variations:
dat khanh » van khanh, duy khanh
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
vai cua » dai cua, hai cua, lai cua
xa hanh » xa thanh, xa khanh, va hanh
van cam » van nam, van lam, van cau
tang ma » tang van
cua tre » cua te, cuu tre, cua triet

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 ((tang ma) OR (mang may)) hoi. hieu van cam tuc ((xa hanh) or (dat khanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((tang ma) OR (mang may)) hoi. hieu van cam tuc ((xa hanh) OR (dat khanh)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((tang ma) OR (mang may)) hoi. hieu van cam tuc ((xa hanh) or (dat khanh)) vai cua tre*".