Bulgarian newspaper content in English is not readily available. Newspapers and articles are not routinely translated. Some English-language content can be found in larger general databases such as EMIS Intelligence or PressReader, but not much, and the offerings are very selective. In addition, some websites have born-digital English-language news content about Bulgaria such as Sofia Globe or Balkan Insight, but they are not necessarily what Bulgarians themselves are reading, although they may be helpful depending on your research needs. Consult the section titled "Online Newspapers from Bulgaria" to learn more about databases.
In the Library of Congress collection there are two newspapers from Bulgaria that were originally published in English, but they are not comprehensive sources for discovering information on a particular topic as it was presented in the Bulgarian press. The first one described below is Sofia News, which ran for many years, but it was written and controlled by the communist authorities, so the content reflects what the government wished to be presented to English-language readers. The second title is Sofia Echo, an English-language newspaper produced for the diplomatic and ex-patriot communities in Bulgaria, thus the content will not cover the breadth of daily Bulgarian or world news. Neither of these titles exists in electronic format, but they are available via interlibrary loan on microfilm.