This guide is an introduction to statistical publications published in Bulgaria, about Bulgaria. It is not meant to be comprehensive, for it is impossible to identify and list every possible source of statistics for Bulgaria. Rather, it presents the most important sources in the collections of the Library of Congress. All titles are annotated for content, and entries provide bibliographic citations, subject headings, links to records in the Library's online catalog, and detailed holdings in the Library's collection. Most annotations are for titles examined in person, but also included are important census publications that are missing from the Library's collections. These items have a note that they are not held.

What is the scope of this guide? It covers materials published from 1878 through the present day. The year 1878 marks the date when Bulgaria achieved semi-independence from the Ottoman Empire. For statistical sources from the Ottoman period, see the guide produced by the International and Area Studies Library of the University of Illinois External. Most publications in this guide are in Bulgarian. Those that are bilingual are noted as such in the annotations. The subjects of annotated publications include censuses, demography, agriculture, public finance, housing, data on specific regions of Bulgaria, and major general resources for Bulgarian statistics.

It does not include materials on economics, business, or banking, because the size of the guide would be unwieldy. It also does not discuss Bulgarian publications that cover statistics of other nations, or publications from other countries about Bulgaria. The organization of the guide is presented in the menu on the left. Within each section, annotated titles are presented in chronological order by publication date and/or dates of coverage.

The main source of statistical data for the 19th through 21st centuries has been a national statistical agency located in Sofia. It was founded in 1880, under the name Statistiko-organizatsionno otdelenie kum Ministerstvoto na finansite, and has undergone several name changes, such as Statistichesko biuro and Tsentralnoto statistichesko upravlenie. Since 1991 it has been called Natsionalen statisticheski institut External (National Statistical Institute or NSI). Its responsibilities include gathering, analyzing, and disseminating statistical data on the Bulgarian economy, culture, and daily life, including conducting censuses of population and housing. In the past, it also conducted agricultural censuses, but today that responsibility belongs to the Ministry of Agriculture, Food and Forestry External. For more details, see the annotation in the section "Online Resources" on the Natsionalen statisticheski institut, as well as the section on agricultural statistics for more on the Ministry of Agriculture, Food and Forestry.

Bulgaria joined the European Union in 2007. Since then, some of its statistical data have been available in EU statistical sources issued by the Statistical Office of the European Union (Eurostat) External. Data from Bulgaria from the time when it was an EU candidate country appear in selected EU publications even before 2007. (This guide will not annotate sources for EU statistics).

When first conceived, this guide was predominantly about printed materials, because very few electronic sources for Bulgarian statistics existed until the early 2000s. The situation has changed dramatically, with an ever-increasing amount of data available online. Beginning in the early 2000s, the Natsionalen statisticheski institut has made many born-digital sources of Bulgarian statistics available on its website. When relevant, e-sources and websites are annotated in the guide. For earlier publications and data from 1878 and forward, the Digital Library of the Natsionalen statisticheski institut External is an outstanding source, with many freely available publications. Because of its richness, this site should be consulted before turning to general international digital libraries, such as Google Books External and HathiTrust External, which are more likely to have viewing restrictions due to copyright laws. When full electronic versions are available, links or a reference to the Natsionalen statisticheski institut website are provided.

One of the first sources to consult for all kinds of statistics is the statistical yearbook (Statisticheski godishnik) for the pre-communist, communist, or post-communist eras. Yearbooks with varying titles have been published in Bulgaria for almost every year since 1909, and they cover many subject areas. If these sources do not provide enough information, then look for more specialized sources.

For materials in the Library of Congress general collections, there are a number of important call number ranges for Bulgarian statistical publications, such as HA1621–1628 (HA = Statistics), HB3627-3628 (HB = Economics), HD2041 (HD = Land, Agriculture, Industry, Labor), and HG3221–3226 (HG = Finance). However, these are not the only call numbers, because statistical compilations exist on many subjects, and are often found under the call numbers for the subjects. For example, statistical volumes on libraries appear under Z (Bibliography and Library Science). Browsing the Library of Congress Online Catalog via a call number search can be useful to see the whole range of available titles.

Also, try searching online catalogs of other libraries or the bibliographic database WorldCat using subject headings such as Bulgaria--Population--Statistics, or Public health--Bulgaria--Statistics, or Bulgaria--Census. The pattern for the subject headings usually includes the words "Bulgaria" and "statistics," and may add more specific subjects, such as public health or housing.

No attempt has been made to interpret the accuracy of statistics produced during the communist era or any other era in Bulgarian history. We simply present the publications and leave interpretation to the user.

The original version of this guide was developed in 2014, as a result of a request from the reference staff at the Slavic Reference Service (SRS) External of the University of Illinois.