Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
nang xa » nang x, lang xa, nang ma
cam duc » cam xuc, cao duc, pham duc
duc van » duc va, duc tan, duc manh
hieu va » hieu qua
v nang » va nang, vu nang, van nang
kem va » kiem va, kiem van

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) OR (thuoc sach)) v nang xa hoi. ((hieu va) or (lieu va)) cam duc van hanh kem va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) v nang xa hoi. ((hieu va) OR (lieu va)) cam duc van hanh kem va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (thuoc sach)) v nang xa hoi. ((hieu va) or (lieu va)) cam duc van hanh kem va triet".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (thuoc sach)) v nang xa hoi. ((hieu va) or (lieu va)) cam duc van hanh kem va triet*.