Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
cua chat » cua cha, chuan chat, cao chat
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
tu bai » tu ban, tu bat, te bai
ca cua » co cua
tu sai » tu san, tu cai, tu lai

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) OR (tu bai)) ky tang ma hoi. hieu cua chat xuc ((va danh) or (van hanh)) ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sai) OR (tu bai)) ky tang ma hoi. hieu cua chat xuc ((va danh) OR (van hanh)) ca cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sai) OR (tu bai)) ky tang ma hoi. hieu cua chat xuc ((va danh) or (van hanh)) ca cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sai) OR (tu bai)) ky tang ma hoi. hieu cua chat xuc ((va danh) or (van hanh)) ca cua tre*.