Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
thanh le » thinh le, thanh ve, thanh de
thu sach » thuat sach, thuoc sach, thu hoach
luc ban » duc ban, cuc ban, luc bat
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
tu sach » te sach, tu cach, vu sach
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
le cua » ly 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 (thu sach))) or (su sach)) ky dang xa hoi. hieu van cau luc ban thanh le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thu sach))) OR (su sach)) ky dang xa hoi. hieu van cau luc ban thanh le cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((tu sach) OR (thu sach))) or (su sach)) ky dang xa hoi. hieu van cau luc ban thanh le cua tre".
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) OR (thu sach))) or (su sach)) ky dang xa hoi. hieu van cau luc ban thanh le cua tre*.