Perhaps you should try some spelling variations:
sang tao » hang tai
su sach » so sach, vu sach
sang ma » tang ma, nang ma, mang may
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
bai so » dai so, tai so, hai so
va cua » va chua, via cua, ca cua
so va » so van, so vat, su va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((sang ma) or (sang tao)) hoi. hieu va bai so va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((sang ma) OR (sang tao)) hoi. hieu va bai so va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y ((sang ma) or (sang tao)) hoi. hieu va bai so va hanh va cua tre*.