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

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