Clutch failure when pulling off motorway

[dcurzon]

As I went up the slip road, there was no pressure on my clutch lever as I went to drop through the gears. Managed to slip into neutral and onto the side. 3 out of 5 bolts had at some point rattled loose and gone, and the remaining 2 were loose!
(Left side sprocket cover), so when I was trying to pull the lever, the casing was moving instead of moving the clutch.

Tightened up the remaining 2 bolts and was able to get home.

Where can I get these bolts??

Cheers