Perhaps you should try some spelling variations:
hanh thoi » hanh thuoc, nhanh thai, hanh noi
thoi cua » hoi cua, thai cua, troi cua
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
va lam » van lam, va lap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang ma) OR (tang ma)) hoa. hieu va lam ((duc va) OR (truc va)) hanh thoi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang ma) OR (tang ma)) hoa. hieu va lam ((duc va) or (truc va)) hanh thoi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang ma) OR (tang ma)) hoa. hieu va lam ((duc va) or (truc va)) hanh thoi cua tre*.