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