J. J. Sojka, R. W. Schunk, and M. J. Nicolls. Ionospheric Ion Temperature Forecasting in Multiples of 27 Days. Space Weather, volume 12, pages 148-160,  2014 .

J. J. Sojka, M. Nicolls, A. van Eyken, C. Heinselman, and D. Bilitza. 24/7 Solar minimum polar cap and auroral ion temperature observations. Advances in Space Research, volume 48,  2011 .

J. J. Sojka, M. J. Nicolls, C. J. Heinselman, and J. D. Kelly. The PFISR IPY observations of ionospheric climate and weather. J. Atmos. Solar-Terr. Phys., volume 71, issue 6, pages 771-785,  2009 .

J. J. Sojka, R. L. McPherron, A. P. van Eyken, M. J. Nicolls, C. J. Heinselman, and J. D. Kelly. Observations of ionospheric heating during the passage of solar coronal hole fast streams. Geophys. Res. Lett., volume 36, issue 1,  2009 .

P. G. Richards, M. J. Nicolls, C. J. Heinselman, J. J. Sojka, J. M. Holt, and R. R. Meier. Measured and modeled ionospheric densities, temperatures, and winds during the international polar year. J. Geophys. Res., volume 114,  2009 .