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Pergamum (Extinct city) - LC Linked Data Service: Authorities and Vocabularies | Library of Congress

found: Oxford classical dictionary, 3rd. ed. electronic ed, Feb. 23, 2010:(Pergamum; in Mysia, Turkey, 15 miles from the Aegean sea, a natural fortress of great strategic importance commanding the rich plain of the river Caïcus; important historically as the capital of the Attalid kings and, later, as one of the three leading cities of provincial Asia, and archaeologically as the only excavated Hellenistic royal capital outside Macedonia)

found: Britannica online, Feb. 23, 2010:(Pergamum; Greek: Pergamon; ancient Greek city in Mysia, situated 16 miles from the Aegean Sea on a lofty isolated hill on the northern side of the broad valley of the Caicus (modern Bakir) River; the site is occupied by the modern town of Bergama, in the province of Izmir, Turkey; Pergamum existed at least from the 5th century BC, but it became important only in the Hellenistic Age (323-30 BC), when it served as the residence of the Attalid dynasty)

found: Marcellesi, M.-C. Pergame: de la fin du Ve au début du Ier siècle avant J.-C. : pratiques monétaires et histoire, 2012.