Perhaps you should try some spelling variations:
thanh lap » phan lap, thanh hai, thanh van
hieu sau » hieu su, hieu suat, tieu su
tang van » dang van, hoang van, trong van
pham duy » pham duc
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
van hoc » van hoa
ty tang » tay tang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
duy va » duy vat, duy van, day va

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 ty tang van hoc. ((hieu ve) or (hieu sau)) pham duy va ((thanh lap) OR (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty tang van hoc. ((hieu ve) OR (hieu sau)) pham duy va ((thanh lap) OR (thanh san)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty tang van hoc. ((hieu ve) or (hieu sau)) pham duy va ((thanh lap) OR (thanh san)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty tang van hoc. ((hieu ve) or (hieu sau)) pham duy va ((thanh lap) OR (thanh san)) cua tre*.