Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
hanh de » hanh ve, hanh kem
va hanh » van hanh, va thanh, va danh
va nang » van nang, da nang, cam nang
hieu va » hieu qua
de cua » le cua, te cua, dieu cua
luc va » duc va, tuc va, loc va
cua te » cua tu
v nang » vu nang, van nang, voi nang

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