Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu luc » hieu luat, hieu qua
luc chat » luc nhat, luu chat, muc chat
chat xuc » chat huu, cam xuc, chao xu
ban hanh » ban hang
tu sach » thu sach, su sach, tu cach
te sach » toc sach
xang xa » lang xa, mang xa, ang xa
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di 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) OR (te sach)) ty xang xa hoi. hieu luc chat xuc ((van thanh) or (ban hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ty xang xa hoi. hieu luc chat xuc ((van thanh) OR (ban hanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ty xang xa hoi. hieu luc chat xuc ((van thanh) or (ban hanh)) vi cua tre*".