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 » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
2 nang » v nang
sach 2 » sach y
de va » de van, te va, ke va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach 2 nang xa hoi. ((hieu va) or (lieu va)) cam duc ((va hanh) OR (va danh)) de va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach 2 nang xa hoi. ((hieu va) OR (lieu va)) cam duc ((va hanh) OR (va danh)) de va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach 2 nang xa hoi. ((hieu va) or (lieu va)) cam duc ((va hanh) OR (va danh)) de va triet*".