Perhaps you should try some spelling variations:
van thanh » van tuan
ban thanh » ban hanh, ban hang
van hanh » ban hanh, van anh, van ban
hanh ca » hanh cac, hanh cat, hanh cua
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, mang may
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
ca cua » co cua

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