1. A. Ja. Hinčin, On unimodal distributions,Izv. Naučno-Issled. Inst. Mat. Meh. Tomsk. Gos. Univ. 2 (1938), 1–7 (in Russian with German summary).
2. A. Wintner, Cauchy's stable distributions and an “explicit formula” of Mellin,Amer. J. Math. 78 (1956), 819–861.
3. I. A. Ibragimov, O kompozicii odnoveršinnyh raspredeleniĩ,Teor. Verojatnost. i Primenen. 1 (1956), 283–288.
4. I. A. Ibragimov andK. E. Černin, Ob odnoveršinnosti ustoîčivyh zakonov,Teor. Verojatnost. i Primenen. 4 (1959), 453–456.
5. E. Lukács, Recent developments in the theory of characteristic functions,Proc. Fourth Berkeley Sympos. Math. Statist. Probability, Vol. II, Berkeley-Los Angeles, 1961, 307–335.