Government Instruction No. RD-02-20-12 of 03 August 2012 for the transformation of the existing geodetic and cartographic materials and data into "Bulgarian Geodesic System 2005" was published in State Gazette issue 63 of 17 August 2011.
The manual describes the existing geodetic coordinate systems in the country as well as all practical steps enabling the coordinates of the geodetic and cartographic materials and data used in the BGC 2005 coordinate system to be transformed.
Also, AGKK publishes the official software product BGSTrans 4.0 to perform all kinds of transformations described in Instruction # RD-02-20-12 of 03 August 2012. The software is free to download.