Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
thuc dang » thuoc dang, thuc dan, thuc dung
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va triet » va trien, cua triet, va viet
ve triet » va trien, su triet
so sach » so sanh, bo sach, co sach
sang ma » tang ma, nang ma, sang tao
y sang » _ sang, duy sang
ma hoi » mai hoi, xa hoi, ma hoa
thiet » thieu

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 y sang ma hoi. hieu van nam thuc dang hanh vi ((((va triet) OR (ve triet))) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y sang ma hoi. hieu van nam thuc dang hanh vi ((((va triet) OR (ve triet))) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y sang ma hoi. hieu van nam thuc dang hanh vi ((((va triet) OR (ve triet))) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: so sach y sang ma hoi. hieu van nam thuc dang hanh vi ((((va triet) OR (ve triet))) or (va thiet))*.