Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
tu cach » tu cac
hieu va » lieu va, hieu qua
te sach » toc sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (te sach)) ky ((nang xa) or (nang ma)) hoi. hieu va cam thuc van hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (te sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va cam thuc van hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (te sach)) ky ((nang xa) or (nang ma)) hoi. hieu va cam thuc van hanh dai cua te*.