Perhaps you should try some spelling variations:
chat thuc » thuat thuc, nhan thuc, chat thai
dua tren » dung tren
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((nang xa) or (lang xa)) hoi. hieu ve chat thuc va hanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((nang xa) OR (lang xa)) hoi. hieu ve chat thuc va hanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((nang xa) or (lang xa)) hoi. hieu ve chat thuc va hanh vi ((dua tren) or (cuu tre))*.