Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
che duoc » che thuoc, che do, te duoc
van hanh » van thanh, ban hanh, van anh
ky sang » ky dang, ky tang, duy sang
hieu ve » hieu va, hieu van
va hanh » va thanh, va danh, ban hanh
hoi cua » hoi chuc
cua tre » cua te, cuu tre, cua triet
ve che » va che, ke che, de che

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 ((ky sang) or (ky nang)) ma hoa. hieu ve che duoc ((va hanh) or (van hanh)) hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky sang) OR (ky nang)) ma hoa. hieu ve che duoc ((va hanh) OR (van hanh)) hoi cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky sang) or (ky nang)) ma hoa. hieu ve che duoc ((va hanh) or (van hanh)) hoi cua tre*.