Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
toc sach » hoc sach, doc sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
thu bang » thu ban, thu hang, chu bang
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cua viet » ca viet, hoa viet, cua vat
bang ma » bang may, tang ma, ban ma
thuc va » thuc vat, thuc dan, thuc day
dinh vi » dinh ve, dinh viet, dinh tri
ma hoi » mai hoi, xa hoi, ma hoa

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 thu bang ma hoi. hieu van cham thuc va ((dinh vi) OR (chinh tri)) cua viet~.
• Adding a wildcard symbol may retrieve word variants: toc sach thu bang ma hoi. hieu van cham thuc va ((dinh vi) or (chinh tri)) cua viet*.