Perhaps you should try some spelling variations:
nhanh thang » nhanh thanh, nhanh quang, hanh trang
nhanh lang » nhanh quang, nhan dang, nhanh dong
hieu sach » chieu sach, hieu cach, dien sach
doc hieu » toc thieu, hoc thieu, hoc hien
luan han » luan hoan, luan phan, luan van
nong tap » tong tap, nhung tap, cuong tap
nong tan » cong tan, nong dan, nong san
doan cau » toan cau, doan dau, doan cap

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: doc hieu sach - ((nhanh thang) OR (nhanh lang)) luan han ((nong tap) OR (nong tan)) doan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sach - ((nhanh thang) or (nhanh lang)) luan han ((nong tap) OR (nong tan)) doan cau~".
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - ((nhanh thang) or (nhanh lang)) luan han ((nong tap) OR (nong tan)) doan cau*.