Perhaps you should try some spelling variations:
cac cach » cai cach, cuoc cach, va cach
hang vi » hang va, hanh vi, khang voi
hang di » hang doi, hang dien, hang dich
cua tre » cua te, cuu tre, cua triet
cac bac » cac bai, cac ban, sach bac
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang xa hoi. hieu ve ((cac bac) or (cac cach)) ha ((hang di) OR (hang vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang xa hoi. hieu ve ((cac bac) OR (cac cach)) ha ((hang di) OR (hang vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang xa hoi. hieu ve ((cac bac) or (cac cach)) ha ((hang di) OR (hang vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang xa hoi. hieu ve ((cac bac) or (cac cach)) ha ((hang di) OR (hang vi)) cua tre*.