Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
dan thanh » dang thanh, danh thanh, ban thanh
hieu van » hieu va, thien van, lieu va
lang van » dang van, hoang van, giang van
thuc dan » thuc hanh, hoc dan, thuc vat
tang van » dang van, hoang van, trong van
cam thuc » am thuc, nam thuc, cam thu
doi cua » dai cua, hoi cua
van cam » van nam, van lam, van cau
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay
cua tu » cua tuc, cua su, cua cu

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 y ((lang xa) or (((lang van) OR (tang van)))) hoi. hieu van cam thuc dan thanh doi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((lang xa) OR (((lang van) OR (tang van)))) hoi. hieu van cam thuc dan thanh doi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((lang xa) or (((lang van) OR (tang van)))) hoi. hieu van cam thuc dan thanh doi cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach y ((lang xa) or (((lang van) OR (tang van)))) hoi. hieu van cam thuc dan thanh doi cua tu*.