{"id":"001024879","type":"book","title":"The fortification of Birka","publisher":"The National Museum of Denmark, Copenhagen","publisher-place":"Copenhagen","pages":"159-167","container-title":"Maritime warfare in Northern Europe. Technology, organisation, logistics and administration 500 BC-1500 AD. Papers from an International Research Seminar at the Danish National Museum, Copenhagen, 3-5 May 2000","author":[{"family":"Holmquist Olausson","given":"Lena."}],"issued":{"raw":"2002"}}