Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc van » thuc vat, thuc dan, thuc va
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
xay hoi » xa hoi, tay hoi, cay phoi
hieu ve » hieu va
sach ky » sac ky, sach y, sach ty
tuc van » truc van, tuc va, duc van
ky dang » ky nang, ky danh
vi cua » vai cua, di cua
cua te » cua tu

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 ky dang xay hoi. ((hieu ve) OR (hieu van)) cam ((tuc van) OR (thuc van)) hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xay hoi. ((hieu ve) or (hieu van)) cam ((tuc van) OR (thuc van)) hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xay hoi. ((hieu ve) or (hieu van)) cam ((tuc van) OR (thuc van)) hanh vi cua te*.