Perhaps you should try some spelling variations:
nhanh lang » nhanh quang, nhanh thang, nhan dang
nhung cong » thong cong, hang cong, nhung don
tieu sach » chieu sach, dien sach, te sach
hanh tang » hanh trang, anh tang, hanh mang
dung cong » dung trong
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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: theo tieu sach - ((hanh tang) OR (nhanh lang)) va ((nhung cong) OR (dung cong)) tap toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu sach - ((hanh tang) or (nhanh lang)) va ((nhung cong) OR (dung cong)) tap toan cau~".
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - ((hanh tang) or (nhanh lang)) va ((nhung cong) OR (dung cong)) tap toan cau*.