SHARMA, Kanika, and V. RAVICHANDRAN. “Sufficient Conditions for Janowski Starlike Functions”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 61, no. 1, Mar. 2016, pp. 63-76, https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5517.