Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
vi dua » vi du, vi lua
vi dum » vi du
x hoi » xa hoi, o hoi, x ho

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: ((te sach) OR (toc sach)) ky nang x hoi. hieu va cam xuc va hanh ((vi dua) OR (vi dum)) tren~.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. hieu va cam xuc va hanh ((vi dua) or (vi dum)) tren*.