Perhaps you should try some spelling variations:
chat thuc » thuat thuc, chat thai, chat huu
nhan thuc » nhan luc, dan thuc, toan thuc
cua tre » cua te, cuu tre, cua triet
vai cua » dai cua, hai cua, lai cua
don vai » don vi, don va, den vai
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
san ky » sang ky, van ky, dan ky
va don » va dong, va doc, va do
tu san » thu san, tu ban, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky ((nang xa) or (mang may)) hoi. hieu va ((chat thuc) OR (nhan thuc)) va don vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky ((nang xa) OR (mang may)) hoi. hieu va ((chat thuc) OR (nhan thuc)) va don vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky ((nang xa) or (mang may)) hoi. hieu va ((chat thuc) OR (nhan thuc)) va don vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu san ky ((nang xa) or (mang may)) hoi. hieu va ((chat thuc) OR (nhan thuc)) va don vai cua tre*.