Perhaps you should try some spelling variations:
sach kha » sach nha, sach ha, sach tham
kha nang » phap nang, ky nang, ki nang
hanh vai » hanh vi, hanh tai, hanh van
cam thuc » am thuc, nam thuc, can thuc
tu sach » thu sach, su sach, te sach
hanh va » hang va, hanh vi
cam thu » nam thu, cac thu, ca thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach kha nang xa hoi. hieu ve ((cam thuc) OR (cam thu)) va ((hanh vai) or (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach kha nang xa hoi. hieu ve ((cam thuc) OR (cam thu)) va ((hanh vai) OR (hanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach kha nang xa hoi. hieu ve ((cam thuc) OR (cam thu)) va ((hanh vai) or (hanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach kha nang xa hoi. hieu ve ((cam thuc) OR (cam thu)) va ((hanh vai) or (hanh va)) cua tre*.