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
thuc va » thuc vat, thuc dan, thuc day
hanh di » hanh de, hang di, danh di
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho
va am » va lam, va cam

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 am thuc va ((hanh di) OR (hanh vi)) 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 am thuc va ((hanh di) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vu khach)) ky nang x hoi. hieu va am thuc va ((hanh di) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) ky nang x hoi. hieu va am thuc va ((hanh di) OR (hanh vi)) cua tre*.