Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
chat thuc » thuat thuc, nhan thuc, chat thai
thu sach » tu sach, thuoc sach, thu hoach
hieu cua » hieu qua, dieu cua, bieu cua
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ca » hieu cac, hieu va, hieu xa
cua tre » cua te, cuu tre, cua triet
tay ho » tay co, tay o, tay khao
va tay » va thay, van tay, ha tay
ty va » ty van, tay va, tuy va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) OR (thuat sach)) ty va tay ho. ((hieu ca) or (hieu cua)) chat thuc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) ty va tay ho. ((hieu ca) OR (hieu cua)) chat thuc va hanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuat sach)) ty va tay ho. ((hieu ca) or (hieu cua)) chat thuc va hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuat sach)) ty va tay ho. ((hieu ca) or (hieu cua)) chat thuc va hanh dai cua tre*.