Perhaps you should try some spelling variations:
va thuat » ki thuat, va thuc, va thiet
dang xay » dang van, van xay
thuc van » thuc vat, thuc dan, thuc va
te sach » toc sach
dat cua » dai cua, day cua, mat cua
anh dat » thanh dat, lanh dao, dinh dat
van anh » van thanh, tuan anh, van minh
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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 y ((nang xa) or (dang xay)) hoi. hieu ((va thuat) OR (ky thuat)) thuc van anh dat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang xa) OR (dang xay)) hoi. hieu ((va thuat) OR (ky thuat)) thuc van anh dat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((nang xa) or (dang xay)) hoi. hieu ((va thuat) OR (ky thuat)) thuc van anh dat cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang xa) or (dang xay)) hoi. hieu ((va thuat) OR (ky thuat)) thuc van anh dat cua tre*.