Perhaps you should try some spelling variations:
cac thoi » cac toi, cac hop, cac tro
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
thoi va » hoi va, thai va, tho va
so sach » so sanh, bo sach, co sach
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang

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

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