Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cay thuc
can thuc » dan thuc, van thuc, cay thuc
cam thu » nam thu, cac thu, ca thu
hoi cua » hoi chuc
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
nang o » nang co, nang ho, nang ro
cua tu » cua tuc, cua su, cua cu
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky nang o hai. hieu van ((((cam thuc) OR (can thuc))) or (cam thu)) gia thanh hoi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky nang o hai. hieu van ((((cam thuc) OR (can thuc))) OR (cam thu)) gia thanh hoi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky nang o hai. hieu van ((((cam thuc) OR (can thuc))) or (cam thu)) gia thanh hoi cua tu".
• Adding a wildcard symbol may retrieve word variants: vu sac ky nang o hai. hieu van ((((cam thuc) OR (can thuc))) or (cam thu)) gia thanh hoi cua tu*.