Mostova, M.R., and M.V. Zabolotskyj. “Convergence in $L^p[0,2\pi]$-Metric of Logarithmic Derivative and Angular $\upsilon$-Density for Zeros of Entire Function of Slowly Growth”. Carpathian Mathematical Publications, vol. 7, no. 2, Dec. 2015, pp. 209-14, doi:10.15330/cmp.7.2.209-214.