Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
te sach » toc sach
nang xa » nang x, lang xa, nang ma
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

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