Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
vu sach » vu bach, su sach
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de 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 (vu khach)) ky nang x hoi. hieu va cam tuc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky nang x hoi. hieu va cam tuc va hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) ky nang x hoi. hieu va cam tuc va hanh di cua tre*.