Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
luat dung » suat dung, luat chung, thuat dung
dung cong » dung trong
chao chu » cho chu, cua chu, cao cho
chu xanh » chu manh, chieu xanh, chua xang
tap toan » tap doan, tap quan
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: chao chu xanh - hanh trinh luat dung cong ((tap toan) or (bai toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: chao chu xanh - hanh trinh luat dung cong ((tap toan) OR (bai toan)) cau.
• Adding a wildcard symbol may retrieve word variants: chao chu xanh - hanh trinh luat dung cong ((tap toan) or (bai toan)) cau*.