@article{kuznetsov_plotkin_nesterova_izraileva_1993, 
  title={Universal Diurnal Variation of F2-Layer Critical Frequency as Characteristic of Global Ionosphere Condition.}, 
  volume={45}, 
  DOI={10.5636/jgg.45.1175}, 
  number={10}, 
  publisher={Society of Geomagnetism and Earth, Planetary and Space Sciences}, 
  author={Kuznetsov and Plotkin and Nesterova and Izraileva}, 
  year={1993}
  }