BezkorovainaL. L. “Surfaces Generated by the Real and Imaginary Parts of Analytic functions: $A$-Deformations Occurring Independently or Simultaneously”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 70, no. 4, Apr. 2018, pp. 447-63, http://umj.imath.kiev.ua/index.php/umj/article/view/1567.