Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cam thuc » am thuc, nam thuc, cam thu
thuc ban » thuoc ban, thuc dan, thu ban
thanh di » thanh doi, thanh de, thanh do
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
su viet » so viet
va cam » va cham, va cac, va cao
di su » doi su, ki su, da su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((nang xa) or (lang xa)) hoi. hieu va cam thuc ban thanh di su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (lang xa)) hoi. hieu va cam thuc ban thanh di su viet.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (lang xa)) hoi. hieu va cam thuc ban thanh di su viet*.