Perhaps you should try some spelling variations:
te sach » toc sach
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu va, hieu van
do thuc » hoc thuc, dan thuc
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cuu tre » cua tre, cau tren, cau treo
va cuu » va cau, va chu, va huu
ve do » ve dao, ve doi, va do

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 ((tu nang) or (truc nano)) xa hoi. hieu ve do thuc va hanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu nang) OR (truc nano)) xa hoi. hieu ve do thuc va hanh va cuu tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nang) or (truc nano)) xa hoi. hieu ve do thuc va hanh va cuu tre*.