Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
sach ty » sach y, sach tu, sach thu
xang ma » tang ma, nang ma, sang ma
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
thuc va » thuc vat, thuc dan, thuc day
dinh vi » dinh viet, dinh tri, dinh thi
dinh ve » dinh ket, dinh van
ma hoi » mai hoi, xa hoi, ma hoa

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 ty xang ma hoi. hieu va tham thuc va ((((dinh vi) or (dinh ve))) or (chinh tri)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty xang ma hoi. hieu va tham thuc va ((((dinh vi) OR (dinh ve))) OR (chinh tri)) cua viet.
• Adding a wildcard symbol may retrieve word variants: toc sach ty xang ma hoi. hieu va tham thuc va ((((dinh vi) or (dinh ve))) or (chinh tri)) cua viet*.