Meyers Orts- und Verkehrs-Lexikon des Deutschen Reichs (Meyers Gazetteer), online edition, with GOV (genealogy.net) for post-1945 Polish equivalents · meyersgaz.org / gov.genealogy.net
Hammelspring, Templin, Potsdam, Brandenburg, Preussen — 1912 coordinate 53.0714, 13.4319
Only Hammelspring in Meyers; #10385 holds the same Wikidata item Q1500086.