Perhaps you should try some spelling variations:
van thanh » van tuan
ban thanh » ban hanh, ban hang
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
qua cai » qua hai, qua cac, qua ca
vien su » vien sau, nien su, vien du
x hoi » xa hoi, o hoi, x ho
kien » bien, tien, dien

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu nang x hoi. hieu qua cai vuc ((van thanh) OR (ban thanh)) vien su kien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu nang x hoi. hieu qua cai vuc ((van thanh) OR (ban thanh)) vien su kien".
• Adding a wildcard symbol may retrieve word variants: su sach tu nang x hoi. hieu qua cai vuc ((van thanh) OR (ban thanh)) vien su kien*.