Perhaps you should try some spelling variations:
van thanh » van tuan
ban thanh » ban hanh, ban hang
hanh vai » hanh vi, hanh va, hanh tai
van hanh » ban hanh, van anh, van ban
vai cua » dai cua, hai cua, lai cua
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2

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 v ((tang ma) or (nang cao)) hoi. hieu ((van thanh) or (ban thanh)) luc van hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v ((tang ma) OR (nang cao)) hoi. hieu ((van thanh) OR (ban thanh)) luc van hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach v ((tang ma) or (nang cao)) hoi. hieu ((van thanh) or (ban thanh)) luc van hanh vai cua tre*.