Are you sure this is all the button?
As far as i understand, #efp clicks on the center of FOUND area, so if you have clickable only link at the right, than it will not fire a click-command correctly.
Does it solve your problem?
The simplest for me is to use xpath to locate element.
If you can’t use classes or other attributes as a unique identifier, use just a path to it from some known unique element.
As an example:
/html/body/div/div[2]/div[1]/div[3]/div[2]/div[2]/div[4]/div[1]/div[1]/div[4]/div[2]/a
You can copy that link via context menu in browser, when debug mode is enabled: http://i.prntscr.com/dii3on4LSASqCMEgTbpmRQ.png
And you can simplify it if you need, to, example:
//div[1]/div[4]/div[2]/a
or add some identifier in it:
//div[@id=“someIdHere”]/div[4]/div[2]/a