Аккорды к песне Led Zeppelin - Dyer Maker

Basically, it follows the pattern C Am F G (all  E-form bar 
chords): 
 
C     Am     F  G 
Oh oh oh oh oh, you don`t have to go, ... 
 
repeated endless number of times, until: 
 
Am                         G 
When I read the letter you wrote me, ... 
 
which also repeats a few times before going back to the verse.