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

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