Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, cua triet
ve triet » va trien, su triet
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
dinh vi » dinh ve, dinh viet, dinh tri
nang ma » tang ma, sang ma, nang cao
thuc va » thuc vat, thuc dan, thuc day
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang ma hoi. hieu ve cham thuc va ((dinh vi) or (chinh tri)) ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ma hoi. hieu ve cham thuc va ((dinh vi) OR (chinh tri)) ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ma hoi. hieu ve cham thuc va ((dinh vi) or (chinh tri)) ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ma hoi. hieu ve cham thuc va ((dinh vi) or (chinh tri)) ((va triet) OR (ve triet))*.