Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
duoc ban » duc ban, quoc ban, buoc ban
nam duoc » nam thuoc, da duoc, dat duoc
nang co » nang cao, nang doc, nang noi
sach ly » sach y, sach ty, sach hay
sach lo » sach dao, sach doi, sach hoi
co hoi » co hoc, co loi
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ly) OR (sach lo)) nang co hoi. hieu van nam duoc ban hanh ((vi cua) OR (di cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ly) OR (sach lo)) nang co hoi. hieu van nam duoc ban hanh ((vi cua) or (di cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ly) OR (sach lo)) nang co hoi. hieu van nam duoc ban hanh ((vi cua) or (di cua)) triet*.