  Quantum spheres are among the most studied examples of compact quantum
spaces, described by C*-algebras which are Cuntz-Krieger algebras of a directed
graph, as proved by Hong and Szyma\'nski in 2002. About five years earlier, in
1997, Sheu proved that the C*-algebra of a quantum sphere is a groupoid
C*-algebra. Here we show that the path groupoid of the directed graph of Hong
and Szyma\'nski is isomorphic to the groupoid discovered by Sheu.
