History of Pomerania (1945 present, Yalta ConferencePotsdam Agreement, Former eastern territories of Germany, Recovered Territories, Territorial changes of Germany, Territorial changes of Poland, Flight and expulsion of Germans from Poland during and after World War II, Mecklenburg- Vorpommern, Western Pomerania, Pomeranian Voivodeship, West Pomeranian Voivodeship, Pomerania euroregion