Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
thanh di » thanh de, thanh do, thanh dinh
thuc van » thuc vat, thuc dan, thuc va
tang van » dang van, hoang van, trong van
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
van hoi » van hoa, van hoc, van hoe
cua tre » cuu tre, cua triet, dua tren
sach o » sach lo, sac o, sach y
o tang » do tang, 6 tang, 7 tang
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach o tang van hoi. hieu ve pham thuc van ((thanh di) or (thanh doi)) ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach o tang van hoi. hieu ve pham thuc van ((thanh di) OR (thanh doi)) ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach o tang van hoi. hieu ve pham thuc van ((thanh di) or (thanh doi)) ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach o tang van hoi. hieu ve pham thuc van ((thanh di) or (thanh doi)) ((cua tre) OR (cua te))*.