I found these on Autobarn.com. I imagine one of them is the springs, and one of them is the adjusters.
BRAKE SELF ADJUSTING REPAIR KIT
CARLSON H2644 SELF ADJUSTER REPAIR KIT
Note: self adjusting repair; rear; 225 x 45 drum $16.12
BRAKE DRUM HARDWARE KIT
CARLSON H7287 DRUM HARDWARE KIT
Note: drum all-in-one kit; rear; 225 x 45 drum $11.39
You should be able to get them anywhere. Remember that working on drums can be a pain! Make sure you have a good repair manual. You may also need a special tool, like a spanner.
1999 540iA Sport
Former 93 SSEi Owner
Former 89 SE Owner