Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
phan thuc » nhan thuc, phap thuc, pham thuc
thuc day » thuc dan, thuc vat
may nang » may nong, ky nang, cam nang
hieu van » hieu va, thien van, lieu va
canh may » canh tay, hanh may, mang may
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
so canh » so sanh, bo canh, so danh
hieu ve » hieu va
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: so canh may nang x hoi. ((hieu ve) OR (hieu van)) phan thuc day thanh ((vai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so canh may nang x hoi. ((hieu ve) OR (hieu van)) phan thuc day thanh ((vai cua) OR (lai cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so canh may nang x hoi. ((hieu ve) OR (hieu van)) phan thuc day thanh ((vai cua) or (lai cua)) tre*".