Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
vat hanh » vat thanh, van hanh, va hanh
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
cac thu » cach thuc, cac thoi
thu vat » thuc vat, thu va, thuat vat
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
cua tu » cua tuc, cua su, cua cu

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 van) or (lieu va)) cac thu vat hanh vi ((cuu tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. ((hieu van) OR (lieu va)) cac thu vat hanh vi ((cuu tre) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. ((hieu van) or (lieu va)) cac thu vat hanh vi ((cuu tre) or (cua tu))*.