Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
dan thanh » dang thanh, danh thanh, ban thanh
phap hoc » phap hoan, phap mo, phap han
dang xay » dang van, van xay
so sach » so sanh, bo sach, hoc sach
hai cua » thai cua, dai cua, hoi cua
va phap » va phat, ban phap
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
co sach » bo sach, cuon sach, hoc sach
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (co sach)) ty ((lang xa) OR (dang xay)) hoi. hieu va phap hoc dan thanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (co sach)) ty ((lang xa) OR (dang xay)) hoi. hieu va phap hoc dan thanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (co sach)) ty ((lang xa) OR (dang xay)) hoi. hieu va phap hoc dan thanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (co sach)) ty ((lang xa) OR (dang xay)) hoi. hieu va phap hoc dan thanh hai cua tre*.