In some problems of directional data, finite mixtures of simple distributions have been proposed as statistical models. In this paper we show that for a wide class of directional distributions, all such mixtures are identifiable.
"Identifiability of Finite Mixtures for Directional Data." Ann. Statist. 11 (3) 984 - 988, September, 1983. https://doi.org/10.1214/aos/1176346264