Perhaps you should try some spelling variations:
thien van » thi van
cua triet » cua viet, su triet, va triet
hieu van » hieu va, lieu va, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
sach v » sach va, sach y, sach vay
sach 2 » sach y
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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: su ((sach v) OR (sach 2)) nang x hoi. ((hieu van) OR (thien van)) nam thuc dan hanh vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach v) or (sach 2)) nang x hoi. ((hieu van) OR (thien van)) nam thuc dan hanh vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: su ((sach v) or (sach 2)) nang x hoi. ((hieu van) OR (thien van)) nam thuc dan hanh vi cua triet*.