Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
xuc van » duc van, luc van, xuc ban
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
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: hoc ((sach ky) OR (sac ky)) nang xa hoi. ((hieu ve) or (hieu van)) cam xuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ky) OR (sac ky)) nang xa hoi. ((hieu ve) OR (hieu van)) cam xuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ky) OR (sac ky)) nang xa hoi. ((hieu ve) or (hieu van)) cam xuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ky) OR (sac ky)) nang xa hoi. ((hieu ve) or (hieu van)) cam xuc van hanh vi cua tre*.