Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
day nhanh » day thanh, duy nhanh, dac nhan
day hanh » day thanh, dao hanh, day manh
khach ky » hanh ky, thanh ky
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
hieu ve » hieu va
doi cua » dai cua, hoi 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 khach ky nang x hoi. ((hieu ve) or (hieu van)) cham thuc ((day hanh) or (day nhanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach ky nang x hoi. ((hieu ve) OR (hieu van)) cham thuc ((day hanh) OR (day nhanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu khach ky nang x hoi. ((hieu ve) or (hieu van)) cham thuc ((day hanh) or (day nhanh)) doi cua tre*.