Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cac thuc » cach thuc, cac thu, can thuc
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau tren, cau triet
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
su sach » so sach, vu sach
cuu tre » cua tre, cau tren
van cac » van hac, van cau, van bac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu khach) or (su sach)) ky dang xa hoi. hieu van cac thuc van hanh vi ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (su sach)) ky dang xa hoi. hieu van cac thuc van hanh vi ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu khach) or (su sach)) ky dang xa hoi. hieu van cac thuc van hanh vi ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: ((vu khach) or (su sach)) ky dang xa hoi. hieu van cac thuc van hanh vi ((cuu tre) OR (cau treo))*.