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

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) or (do sanh)) y lang xa hoi. hieu van cam thuc dan thanh doi ((cua tu) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (do sanh)) y lang xa hoi. hieu van cam thuc dan thanh doi ((cua tu) OR (cua cu)).
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (do sanh)) y lang xa hoi. hieu van cam thuc dan thanh doi ((cua tu) or (cua cu))*.