@phdthesis{Pohlen2009,
  author      = {Timo Pohlen},
  title       = {The Hadamard product and universal power series},
  type        = {doctoralthesis},
  school      = {Universit{\"a}t Trier},
  doi       = {10.25353/ubtr-xxxx-e113-be58},
  year        = {2009},
}