Perhaps you should try some spelling variations:
tranh trong » tran trong, trinh trong, anh trong
hien hanh » dieu hanh
trong kha » trong khoa, trong nha, trong ha
nang cong » nang song, dang cong, bang cong
kha nang » phap nang, ky nang, ki nang
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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: hoc hien hanh - tranh trong kha nang cong ((dan toan) OR (van toan)) ban~.
• Adding a wildcard symbol may retrieve word variants: hoc hien hanh - tranh trong kha nang cong ((dan toan) or (van toan)) ban*.