Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
lang van » dang van, tang van, hoang van
vu sach » vu bach, vu khach
hieu ve » hieu va, hieu van
van hoc » van hoa
ky lang » ky nang, ky dang, ky tang
su sach » so sach
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) ky lang van hoc. hieu ve cac tu ((va thanh) OR (ban thanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky lang van hoc. hieu ve cac tu ((va thanh) OR (ban thanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky lang van hoc. hieu ve cac tu ((va thanh) OR (ban thanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky lang van hoc. hieu ve cac tu ((va thanh) OR (ban thanh)) va cua tre*.