1. B. Y. Levin, Distribution of Zeros of Entire Functions (GITTL, Moscow, 1956) [in Russian].
2. A. Yu. Popov, “The least possible type under the orderρ < 1 of canonical products with positive zeros of a given upper ρ-density,” Vestnik Moskov. Univ. Ser. I Mat. Mekh. No. 1, 31–36 (2005) [Moscow Univ. Math. Bull. 60 (1), 32–36 (2005)].
3. A. Denjoy, “Sur les produits canoniques d’ordre infini,” J. de Math. (6) 6, 1–136 (1910).