Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
day hanh » day thanh, dao hanh, day manh
vu khach » vu khanh, vu khac, vay khach
cam thuc » am thuc, nam thuc, cam thu
vu sach » vu bach, su sach
doi cua » dai cua, hoi cua
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) doi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky nang o hoi. hieu ve cam thuc ((day hanh) OR (day nhanh)) doi cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) ky nang o hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) doi cua te*".