Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
doc sach » hoc sach, toc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
hai thuc » thai thuc, ha thuc, hai thu
dai thuc » dan thuc, dai thu, dai thua
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, dai cua

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. hieu van ((hai thuc) or (dai thuc)) ban thanh ((tai cua) or (tri cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky dang xa hoi. hieu van ((hai thuc) OR (dai thuc)) ban thanh ((tai cua) OR (tri cua)) te.
• Adding a wildcard symbol may retrieve word variants: doc sach ky dang xa hoi. hieu van ((hai thuc) or (dai thuc)) ban thanh ((tai cua) or (tri cua)) te*.