Perhaps you should try some spelling variations:
chat duc » chat xuc, chat doc, chet duoc
hanh dai » hanh tai, hanh dao, vanh dai
tu sach » thu sach, su sach, te sach
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet

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 ((ky tang) or (ky dang)) mai hoi. hieu ve chat duc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (ky dang)) mai hoi. hieu ve chat duc va hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) or (ky dang)) mai hoi. hieu ve chat duc va hanh dai cua tre*.