Question: Who is Anton-Günther, Duke Of Oldenburg's father?
Sentence (from "Princess Helena of Waldeck and Pyrmont (1899–1948)"): Princess Helena of Waldeck and Pyrmont (22 December 189918 February 1948) was the only daughter of Friedrich, Prince of Waldeck and Pyrmont, last reigning Prince of Waldeck and Pyrmont, and wife of Nikolaus, Hereditary Grand Duke of Oldenburg.
Relevant evidence: Yes