Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, can thuc
cam thu » nam thu, cac thu, ca thu
cua suc » cua duc, cua tuc, cua cuc
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
nang o » nang co, nang ho, nang ro
cua su » qua su
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 (cam thu)) gia thanh hai ((cua su) or (cua suc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky nang o hai. hieu van ((cam thuc) OR (cam thu)) gia thanh hai ((cua su) OR (cua suc)).
• Adding a wildcard symbol may retrieve word variants: vu sac ky nang o hai. hieu van ((cam thuc) or (cam thu)) gia thanh hai ((cua su) or (cua suc))*.