Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
nhanh mang » nhanh lang, nhanh quang, nhanh thang
tieu xanh » tieu danh, chieu xanh, dieu hanh
hanh mang » hanh trang, nhanh lang, thanh hang
cua nhung » va nhung
tan toan » tan tran, tap toan, van toan
bai toan » bai 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 xanh - ((hanh mang) OR (nhanh mang)) cua nhung cong ((tan toan) OR (bai toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu xanh - ((hanh mang) OR (nhanh mang)) cua nhung cong ((tan toan) or (bai toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: theo tieu xanh - ((hanh mang) OR (nhanh mang)) cua nhung cong ((tan toan) or (bai toan)) cau*.