Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh vi » hanh vi, thanh va, thanh ve
cac thuc » cach thuc, cac thu, can thuc
so sach » bo sach, co sach, hoc sach
cua tre » cua te, cua triet, dua tren
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
so sanh » do sanh
cuu 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) or (so sanh)) y nang xa hoi. hieu va cac thuc vat thanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) y nang xa hoi. hieu va cac thuc vat thanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) y nang xa hoi. hieu va cac thuc vat thanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) y nang xa hoi. hieu va cac thuc vat thanh vi ((cua tre) OR (cuu tre))*.