Ponnusamy, Saminathan, and Karl-Joachim Wirths. 2014. “On the Problem of Gromova and Vasil’ev on Integral Means, and Yamashita’s Conjecture for Spirallike Functions”. Annales Fennici Mathematici 39 (2):721-31. https://doi.org/10.5186/aasfm.2014.3922.