Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh hoai
thanh do » thanh de, thanh pho, thanh hoa
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, can thuc
so sach » so sanh, bo sach, co sach
cam thu » nam thu, cac thu, ca thu
lang xa » lang ha, dang xay, lang van
y lang » o lang, _ lang, tay lang
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 hoi. hieu van ((cam thuc) or (cam thu)) dan ((thanh doi) or (thanh do)) cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y lang xa hoi. hieu van ((cam thuc) OR (cam thu)) dan ((thanh doi) OR (thanh do)) cua tu.
• Adding a wildcard symbol may retrieve word variants: so sach y lang xa hoi. hieu van ((cam thuc) or (cam thu)) dan ((thanh doi) or (thanh do)) cua tu*.