Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
doan vi » don vi, doan thi, doan van
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du
dan vi » don vi, dan va, gan vi

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

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