Knopfmacher, A., A. M. Odlyzko, B. Pittel, L. B. Richmond, D. Stark, G. Szekeres, and N. C. Wormald. “The Asymptotic Number of Set Partitions With Unequal Block Sizes”. The Electronic Journal of Combinatorics 6, no. 1 (October 21, 1998): R2. Accessed March 15, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v6i1r2.