Perhaps you should try some spelling variations:
vien cac » vien dai, vien da, gian cac
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang x hoi. hieu ((vien cac) OR (vien bach)) xuc ((va hanh) or (gia thanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. hieu ((vien cac) OR (vien bach)) xuc ((va hanh) OR (gia thanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. hieu ((vien cac) OR (vien bach)) xuc ((va hanh) or (gia thanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. hieu ((vien cac) OR (vien bach)) xuc ((va hanh) or (gia thanh)) vai cua tre*.