Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
sach bai » sach dao, cac bai, sach xa
bai nang » dai nang, bai tang, ban nang
van hanh » ban hanh, van anh, van ban
te sach » toc sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
di cua » dai cua, doi cua, de cua
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach bai nang xa hoi. ((hieu ve) or (hieu va)) cac duc ((van hanh) or (van thanh)) di cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach bai nang xa hoi. ((hieu ve) OR (hieu va)) cac duc ((van hanh) OR (van thanh)) di cua cu.
• Adding a wildcard symbol may retrieve word variants: te sach bai nang xa hoi. ((hieu ve) or (hieu va)) cac duc ((van hanh) or (van thanh)) di cua cu*.