Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
va hanh » van hanh, va thanh, va danh
va cao » va co, va dao, va bao

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