Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
thu sach » tu sach, thuat sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
dang xay » dang van, van xay
loai va » loai nam
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
lang xa » lang ha, lang van
va dao » ca dao
va tre » va trien

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 thu ((lang xa) OR (dang xay)) hoi. hieu ve pham thuc ((va dao) or (cac dan)) loai va tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach thu ((lang xa) OR (dang xay)) hoi. hieu ve pham thuc ((va dao) OR (cac dan)) loai va tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach thu ((lang xa) OR (dang xay)) hoi. hieu ve pham thuc ((va dao) or (cac dan)) loai va tre".
• Adding a wildcard symbol may retrieve word variants: thu sach thu ((lang xa) OR (dang xay)) hoi. hieu ve pham thuc ((va dao) or (cac dan)) loai va tre*.