Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
tac vang » cac van, tac dung, tac dong
sach ky » sac ky, sach y, sach ty
hang vi » hang va, hanh vi, khang voi
hang di » hang doi, hang dien, hang dich
cac tac » cac toc, cac bac, cac dac
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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: co sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac tac vang ((hang di) or (hang vi)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac tac vang ((hang di) OR (hang vi)) va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac tac vang ((hang di) or (hang vi)) va triet*".