Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
nang xa » nang x, lang xa, nang ma
cac xuc » cam xuc, cac nuoc, chat xuc
va tinh » may tinh
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
cai ky » cao ky, cac ky, sai ky
cam ky » cao ky, cac ky
ca cuu » cap cuu, cua cuu, ca 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 ((cai ky) OR (cam ky)) nang xa hoi. hieu cua cac xuc ((va tinh) or (va hanh)) ca cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((cai ky) OR (cam ky)) nang xa hoi. hieu cua cac xuc ((va tinh) OR (va hanh)) ca cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((cai ky) OR (cam ky)) nang xa hoi. hieu cua cac xuc ((va tinh) or (va hanh)) ca cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu ((cai ky) OR (cam ky)) nang xa hoi. hieu cua cac xuc ((va tinh) or (va hanh)) ca cuu tre*.