Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thu nang » thi nang, thu hang, thu bang
va triet » va thiet, va trien, ve triet
hang doi » hang di, hang loi, huong doi
thuc van » thuc vat, thuc dan, thuc hanh
sach thu » sach thue, sach thieu, sach tham
so sach » so sanh, bo sach, co sach
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve nam » he nam, va nam, le nam

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 thu nang xa hoi. hieu ve nam ((thuc van) OR (thuc va)) hang doi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu nang xa hoi. hieu ve nam ((thuc van) OR (thuc va)) hang doi ((va triet) OR (su triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu nang xa hoi. hieu ve nam ((thuc van) OR (thuc va)) hang doi ((va triet) or (su triet))*".