Source of acquisition is theT︠S︡entralen dŭrzhaven arkhiv (Central State Archives), Fond 285K, Opis 7. The United States Holocaust Memorial Museum Archives received the collection from the T︠S︡entralen dŭrzhaven arkhiv (Bulgaria) via the United States Holocaust Museum International Archives Project in April 2013, and accretion in Nov. 2013. This is an ongoing project.