Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
qua cac » cua cac
cac tuc » cac toc, cac tu, cac tac
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((nang xa) OR (nang x)) hoi. hieu qua cac tuc ((le thanh) or (ban thanh)) ve cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang xa) OR (nang x)) hoi. hieu qua cac tuc ((le thanh) OR (ban thanh)) ve cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) OR (nang x)) hoi. hieu qua cac tuc ((le thanh) or (ban thanh)) ve cua triet".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) OR (nang x)) hoi. hieu qua cac tuc ((le thanh) or (ban thanh)) ve cua triet*.