Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va triet » va thiet, va trien, ve triet
sach thu » sach thue, sach thieu, sach tham
thuc van » thuc dan, thuc va, thuc hanh
thu nang » thi nang, thu hang, thu bang
hieu ve » hieu va, hieu van
hang di » hang doi, hang vi, hang dien
so sach » so sanh, bo sach, co sach
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho

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