Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
ve chat » van chat
va chat » van chat, va phat, cao chat
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
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 sang mai hoi. hieu ((ve chat) or (va chat)) duc va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang mai hoi. hieu ((ve chat) OR (va chat)) duc va hanh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang mai hoi. hieu ((ve chat) or (va chat)) duc va hanh lai cua tre*.