Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu quan » hieu qua, lieu quan, thien quan
trinh qua » trinh quan, trinh cua, trinh quang
hoi hieu » hoi phieu, hoi tieu, moi hieu
hong tap » tong tap, hong thai, thong tai
tap toan » tap doan, tap quan, bai toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu quan - hanh trinh qua (song or dong) hong tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu quan - hanh trinh qua (song OR dong) hong tap toan cao.
• Adding a wildcard symbol may retrieve word variants: hoi hieu quan - hanh trinh qua (song or dong) hong tap toan cao*.