Chervenivanova, Ekaterina, Yavor Christov, and Zapryan Zapryanov. 1996. “On the Motion and Deformation of Two Fluid Particles in an Electric Field”. Ann. Sofia Univ. Fac. Math. And Inf. 88 (December):21-42. https://stipendii.uni-sofia.bg/index.php/fmi/article/view/376.