Български
English 
CONTENTS
- R. Bojilova – Influence of geomagnetic activity on the ionosphere critical frequencies
- E. Oynakov, I. Aleksandrova, D. Solakov – Variations of the parameters of background seismic noise in the stage of preparation of strong earthquakes in the Vrancea regionstorms
- N. Dimitrov, P. Danchev, I. Georgiev – Investigation of the impact of atmospheric refraction on precision leveling measurements
- N. Miloshev, P. Trifonova – What the National Geo information Center is going to change?
- P. Trifonova, M. Metodiev, I. Buchvarov – Digital data records in PAG Geomagnetic Observatory available for a 60 years period
- M. Metodiev, P. Trifonova – Annual report of the observed geomagnetic activity in Panagyurishte Observatory for 2014
- A. Ivanov, I. Georgiev, N. Dimitrov – Analysis of monthly sea level data from Varna tide gauge station
- L. Christoskov, L. Dimitrova, D. Solakov, S. Simeonova – Forty years National Operative Telemetric System for seismological information
- V. Buchakchiev, E. Oynakov, D. Dragomirov, Y. Milkov – Seismicity on the territory of Bulgaria and the adjacent lands recorded by NOTSSI in 2017
- D. Dragomirov, E. Oynakov, V. Buchakchiev, Y. Milkov – Seismicity on the territory of Bulgaria and the adjacent lands recorded by NOTSSI in 2018
