[597] Perm, soviel wie Permische Formation.
Brockhaus-1911: Perm [2] · Perm
Herder-1854: Perm
Lueger-1904: Perm, Permische Formation
Meyers-1905: Perm [3] · Perm [2]
Pierer-1857: Perm [2] · Perm [1]