Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van cau
vat han » vat phan, van han, vat ran
han lai » han tai, han li, phan loai
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu va ky nang ma hoi. hieu van cam thuc vat han lai su triet~.
• Adding a wildcard symbol may retrieve word variants: tu va ky nang ma hoi. hieu van cam thuc vat han lai su triet*.