Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
day nhanh » duy nhanh, dac nhan, day manh
day thanh » dao thanh, dat thanh, da thanh
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
di cua » dai cua, doi cua, de cua
cua te » cua tu
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 ky nang x hoi. ((hieu ve) OR (hieu van)) cham thuc ((day thanh) or (day nhanh)) di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham thuc ((day thanh) OR (day nhanh)) di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham thuc ((day thanh) or (day nhanh)) di cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham thuc ((day thanh) or (day nhanh)) di cua te*.