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
hieu va » lieu va, hieu qua
va cham » va chat, va tham
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sai ky » sac ky
va dan » ca dan, va dao, va dau
di cua » dai cua, doi cua, de 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 xa) OR (nang ma)) hoi. hieu va cham luc ((va hanh) or (va dan)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang xa) OR (nang ma)) hoi. hieu va cham luc ((va hanh) OR (va dan)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((nang xa) OR (nang ma)) hoi. hieu va cham luc ((va hanh) or (va dan)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang xa) OR (nang ma)) hoi. hieu va cham luc ((va hanh) or (va dan)) di cua tre*.