Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
va nang » van nang, da nang, cam nang
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
va hanh » van hanh, va thanh, va danh
v nang » vu nang, van nang, voi nang
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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) OR (va nang)) xa hoi. hieu ve cham duc va hanh ((vi cua) OR (di cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((v nang) or (va nang)) xa hoi. hieu ve cham duc va hanh ((vi cua) OR (di cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((v nang) or (va nang)) xa hoi. hieu ve cham duc va hanh ((vi cua) OR (di cua)) tre*.