Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu su, dieu vu
hieu ve » hieu va, hieu van
soc van » hoc van, oc van, sac van
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: ((te sach) or (thu hoach)) ky nang xa hoi. ((hieu vu) OR (hieu ve)) cham soc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thu hoach)) ky nang xa hoi. ((hieu vu) OR (hieu ve)) cham soc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (thu hoach)) ky nang xa hoi. ((hieu vu) OR (hieu ve)) cham soc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thu hoach)) ky nang xa hoi. ((hieu vu) OR (hieu ve)) cham soc van hanh vi cua tre*.