Bell JP, Burris SN, Yeats KA. Counting Rooted Trees: The Universal Law $t(n)\,\sim\,C \rho^{-n} n^{-3/2}$. Electron. J. Combin. [Internet]. 2006Aug.3 [cited 2026Apr.12];13(1):#R63. Available from: https://www.combinatorics.org/ojs/index.php/eljc/article/view/v13i1r63