Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
sach ly » sach y, sach lo, sach ty
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang
tuc va » thuc va, truc va, duc va

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 ly nang xa hoi. hieu van cac ((tuc va) OR (tuc xa)) hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly nang xa hoi. hieu van cac ((tuc va) OR (tuc xa)) hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly nang xa hoi. hieu van cac ((tuc va) OR (tuc xa)) hanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: so sach ly nang xa hoi. hieu van cac ((tuc va) OR (tuc xa)) hanh vi ((cua tre) or (cuu tre))*.