Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
duc manh » suc manh, duc anh, duc minh
va triet » va thiet, va trien, ve triet
hieu va » hieu qua
duc van » duc va, duc tan, duc phan
hanh de » hanh ve, hanh kem
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
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: thuoc sach v nang x hoi. ((hieu va) or (lieu va)) cam ((duc van) OR (duc manh)) hanh de va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach v nang x hoi. ((hieu va) OR (lieu va)) cam ((duc van) OR (duc manh)) hanh de va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach v nang x hoi. ((hieu va) or (lieu va)) cam ((duc van) OR (duc manh)) hanh de va triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach v nang x hoi. ((hieu va) or (lieu va)) cam ((duc van) OR (duc manh)) hanh de va triet*.