Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hai thuc » thai thuc, dai thuc, ha thuc
thuc ban » thuoc ban, thuc dan, thu ban
ban hang » ngan hang
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
tai cua » thai cua, tai cuc, hai cua
va hai » van hai, va chai, va khai

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky dang xa hoi. lieu va hai thuc ban hang ((((tai cua) or (dai cua))) or (tri cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky dang xa hoi. lieu va hai thuc ban hang ((((tai cua) OR (dai cua))) OR (tri cua)) te.
• Adding a wildcard symbol may retrieve word variants: doc sach ky dang xa hoi. lieu va hai thuc ban hang ((((tai cua) or (dai cua))) or (tri cua)) te*.