Perhaps you should try some spelling variations:
thanh moi » thanh loi, thanh hoa, thanh hai
thanh doi » thanh loi, thanh do, thanh hoai
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
cac tu » cac thu, cach tu, cac du

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