Perhaps you should try some spelling variations:
thanh dat » thanh hai, thanh van, thanh ha
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
hieu ve » hieu va, hieu van
y sang » duy sang
_ sang » _ san
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
du va » dau va, tu va, su va

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y sang) OR (_ sang)) ma hoi. hieu ve cac du va ((thanh dat) OR (thanh san)) su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y sang) or (_ sang)) ma hoi. hieu ve cac du va ((thanh dat) OR (thanh san)) su triet~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y sang) or (_ sang)) ma hoi. hieu ve cac du va ((thanh dat) OR (thanh san)) su triet*.