Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
dao duc » giao duc, tao duoc
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
tang ma » mang may, tang van
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
vi va » vi van, vai va, vu va

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 ty ((nang xa) or (tang ma)) hoi. hieu ve ((dao duc) or (pham duc)) va tinh vi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (tang ma)) hoi. hieu ve ((dao duc) OR (pham duc)) va tinh vi va trien.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (tang ma)) hoi. hieu ve ((dao duc) or (pham duc)) va tinh vi va trien*.