Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh di » thanh doi, thanh de, thanh do
su sach » so sach, vu sach
tuc ban » thuc ban, truc ban, tu ban
sach ly » sach y, sach lo, sach ty
su viet » so viet
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai
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 ly ((nang xa) or (lang xa)) hoi. hieu ((va cam) OR (va cao)) tuc ban thanh di su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly ((nang xa) OR (lang xa)) hoi. hieu ((va cam) OR (va cao)) tuc ban thanh di su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly ((nang xa) or (lang xa)) hoi. hieu ((va cam) OR (va cao)) tuc ban thanh di su viet".
• Adding a wildcard symbol may retrieve word variants: su sach ly ((nang xa) or (lang xa)) hoi. hieu ((va cam) OR (va cao)) tuc ban thanh di su viet*.