The USC Digital Library in California has a large Pentecostal and Charismatic Research Archive collection with valuable records, including collections from Eastern Europe. On some pages, you can use a left-side menu to select subcollections.

“At different times and in different parts of the world, Pentecostal and charismatic expressions of Christianity have followed very different courses of development. A fuller contemporary account of these movements is possible if it is grounded in a better historical understanding of the variations from one time and place to another. To address this challenge, the Pentecostal and Charismatic Research Initiative (PCRI) is working with the USC Digital Library to build an online digital archive of primary historical materials – correspondence, organizational records, tracts, sermons, diaries, photographs, oral histories – from different regions of the world. In order to build this resource, PCRI is providing funding to selected seminary and university libraries so that they can digitize and catalog the most important materials from their collections.”