Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
tieu xanh » tieu danh, chieu xanh, dieu hanh
cua nhung » va nhung
anh tang » anh bang, anh dang, anh nang
tang cua » mang cua, hang cua, tang luan
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.

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu xanh - anh tang cua nhung cong ((tan toan) or (bai toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu xanh - anh tang cua nhung cong ((tan toan) OR (bai toan)) tap.
• Adding a wildcard symbol may retrieve word variants: theo tieu xanh - anh tang cua nhung cong ((tan toan) or (bai toan)) tap*.