Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tham xuc » tham nuoc, tham thuc, pham duc
dua tren » dung tren
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
xuc va » duc va, tuc va, luc va
vi dua » vi du, vi dum, vi lua
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 tham xuc va danh vi dua tren~.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. hieu va tham xuc va danh vi dua tren*.