Perhaps you should try some spelling variations:
tranh van » tran van, trinh van, thanh van
nang cong » nang song, dang cong, bang cong
theo yeu » theo tieu, thiet yeu, theo chu
yeu tinh » yeu tin, lieu tinh, kieu tinh
tranh va » trang va, trinh va, thanh va
tap toan » tap doan, tap quan, bai toan
ty toan » ly toan, huy toan, tam toan

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: theo yeu tinh - hanh ((tranh va) OR (tranh van)) nang cong ((ty toan) OR (tap toan)) ban~.
• Adding a wildcard symbol may retrieve word variants: theo yeu tinh - hanh ((tranh va) or (tranh van)) nang cong ((ty toan) or (tap toan)) ban*.