Perhaps you should try some spelling variations:
ban thanh » ban hang
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
lang xa » lang ha, dang xay, lang van
cao suc » cao duc
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y lang xa hoi. hieu van ((cao suc) OR (cao su)) ((ban thanh) or (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y lang xa hoi. hieu van ((cao suc) OR (cao su)) ((ban thanh) OR (ban hanh)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y lang xa hoi. hieu van ((cao suc) OR (cao su)) ((ban thanh) or (ban hanh)) vai cua tre*".