Uniqueness property for $C^*$-algebras given by relations with circular   symmetry
  A general method of investigation of the uniqueness property for $C^*$-algebra equipped with a circle gauge action is discussed. It unifies isomorphism theorems for various crossed products and Cuntz-Krieger uniqueness theorem for Cuntz-Krieger algebras. 
B. K. Kwasniewski
math.OA