Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tuan tuc » thuan thuc, luan thuc, tuan tuoi
sach vu » sach tu, sach uu, sach xu
sach va » sach xa, sach ha, sach dao
nang xa » nang x, lang xa, nang ma
tuan tu » tuan thu, tran tu, toan tu
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

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