Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua viet » ca viet, hoa viet, cua vat
thai cua » than cua, tai cuc, tri cua
van nhan » van phan, danh nhan, van khanh
cao duc » dao duc, cao suc, giao duc
tu sach » thu sach, su sach, te sach
sach lo » sach dao, sach doi, sach hoi
hieu va » lieu va
lang xa » lang ha, dang xay, lang van
lo lang » o lang, so lang, le lang

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 lo lang xa hoi. ((hieu va) OR (hieu qua)) cao duc ((van nhan) or (van thanh)) thai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach lo lang xa hoi. ((hieu va) OR (hieu qua)) cao duc ((van nhan) OR (van thanh)) thai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach lo lang xa hoi. ((hieu va) OR (hieu qua)) cao duc ((van nhan) or (van thanh)) thai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach lo lang xa hoi. ((hieu va) OR (hieu qua)) cao duc ((van nhan) or (van thanh)) thai cua viet*.