Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dang xay » dang van, van xay
thanh di » thanh doi, thanh de, thanh do
thuc ban » thuoc ban, thuc dan, thu ban
nam thuc » nam thuoc, am thuc, nam thu
su sach » vu sach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
so sach » so sanh, bo sach, co sach
su viet » so viet
va nam » van nam, ha nam, va nay
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) or (so sach)) ly ((nang xa) or (dang xay)) hoi. hieu va nam thuc ban thanh di su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ly ((nang xa) OR (dang xay)) hoi. hieu va nam thuc ban thanh di su viet.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ly ((nang xa) or (dang xay)) hoi. hieu va nam thuc ban thanh di su viet*.