Perhaps you should try some spelling variations:
hien nhanh » hien hanh, thien thanh, tien thanh
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, anh tang, hanh mang
cua nhung » va nhung
tang cua » mang cua, hang cua, tang luan
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban

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: hoc ((hien nhanh) OR (chieu xanh)) - hanh tang cua nhung cong bai toan ban~.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien nhanh) or (chieu xanh)) - hanh tang cua nhung cong bai toan ban*.