Perhaps you should try some spelling variations:
nang noi » nang doc
cam thuc » nam thuc, cam thu, can thuc
su sach » so sach, vu sach
noi hoi » noi doi, doi hoi, hoi hoi
hieu va » lieu va, hieu qua
hai cua » thai cua, dai cua, lai cua
hoi cua » hoi chuc
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang noi hoi. hieu va ((cam thuc) OR (am thuc)) gia thanh ((hai cua) or (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang noi hoi. hieu va ((cam thuc) OR (am thuc)) gia thanh ((hai cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang noi hoi. hieu va ((cam thuc) OR (am thuc)) gia thanh ((hai cua) or (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang noi hoi. hieu va ((cam thuc) OR (am thuc)) gia thanh ((hai cua) or (hoi cua)) tre*.