Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
cam duc » cao duc, pham duc, nam duoc
va hanh » van hanh, va thanh, va danh
hanh ke » hanh kem, thanh ke, hanh ky
v nang » va nang, vu nang, van nang
sach v » sach va, sach y, sach 2
ke va » te va

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 v nang xa hoi. ((hieu va) OR (lieu va)) ((cam duc) OR (cam xuc)) va hanh ke va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang xa hoi. ((hieu va) or (lieu va)) ((cam duc) OR (cam xuc)) va hanh ke va triet~".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang xa hoi. ((hieu va) or (lieu va)) ((cam duc) OR (cam xuc)) va hanh ke va triet*.