Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
sai ky » sac ky
ma hoi » xa hoi, ma hoa, me hoi
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
tu sai » tu bai, tu san, tu cai

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

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