A two-parameter family of exchangeable partitions with a simple updating rule is introduced. The partition is identified with a randomized version of a standard symmetric Dirichlet species-sampling model with finitely many types. A power-like distribution for the number of types is derived.
"A Species Sampling Model with Finitely Many Types." Electron. Commun. Probab. 15 79 - 88, 2010. https://doi.org/10.1214/ECP.v15-1532