Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
sach thu » sach thue, sach thieu, sach tham
thuc va » thuc vat, thuc dan, thuc day
thue va » thuyet va, thuc vat, thuat va
sach ty » sach y, sach tu, xach tay
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve cac » va cac, vien cac
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: su ((sach ty) OR (sach thu)) nang xa hoi. hieu ve cac ((thue va) or (thuc va)) hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) nang xa hoi. hieu ve cac ((thue va) OR (thuc va)) hanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach thu)) nang xa hoi. hieu ve cac ((thue va) or (thuc va)) hanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) OR (sach thu)) nang xa hoi. hieu ve cac ((thue va) or (thuc va)) hanh vi va triet*.