Perhaps you should try some spelling variations:
tranh kha » tranh ha, tranh chap, trinh khai
nang cong » nang song, bang cong, hang cong
dang cong » dung cong
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan tap
theo te » theo tu, theo tieu, theo yeu
te sach » toc sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo te sach - canh tranh kha ((nang cong) or (dang cong)) tan ((toan cau) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo te sach - canh tranh kha ((nang cong) OR (dang cong)) tan ((toan cau) OR (toan cao)).
• Adding a wildcard symbol may retrieve word variants: theo te sach - canh tranh kha ((nang cong) or (dang cong)) tan ((toan cau) or (toan cao))*.