Perhaps you should try some spelling variations:
vu khanh » vu thanh, van khanh, duy khanh
vu sach » vu bach, vu khach
su sach » so sach
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua
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) OR (su sach))) or (vu khanh)) ky nang x hoi. hieu va cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((vu sach) OR (su sach))) OR (vu khanh)) ky nang x hoi. hieu va cam xuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((vu sach) OR (su sach))) or (vu khanh)) ky nang x hoi. hieu va cam xuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((((vu sach) OR (su sach))) or (vu khanh)) ky nang x hoi. hieu va cam xuc va hanh vi cua tre*.