Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
quoc ban » quoc bao, quoc lan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
may hoi » may thoi, tay hoi, mai hoi
ty mang » ty hang, tin mang, tri mang
van cam » van nam, van lam, van cau
ve van » le van
te va » tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty mang) OR (ty xang)) may hoi. hieu van cam quoc ban thanh ((ve van) or (te va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty mang) OR (ty xang)) may hoi. hieu van cam quoc ban thanh ((ve van) OR (te va)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty mang) OR (ty xang)) may hoi. hieu van cam quoc ban thanh ((ve van) or (te va)) triet*".