Bushev, D. M., & Kal'chuk, I. V. (2019). Analyticity and other properties of functionals $I\left(f, p\right)=\int_{A}|f(t)|^p dt$ and $n(f,p)=\left(\frac{1}{\mu(A)}\int_{A}|f(t)|^p dt\right)^{\frac{1}{p}}$ as functions of variable $p$. Methods of Functional Analysis and Topology, 25(4), 339-359. https://zen.imath.kiev.ua/index.php/mfat/article/view/737