Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
lang van » dang van, tang van, hoang van
thu sach » thuat sach, thuoc sach, thu hoach
va thanh » gia thanh, va tinh, le thanh
tu sach » su sach, te sach, tu cach
ky lang » ky nang, ky dang, ky tang
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
cua tre » cua te, cuu tre, cua triet

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

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