Pulsars with gigahertz-peaked spectra
  We investigate a high frequency turn-over effect in radio spectra for pulsars with positive or flat spectral index. Using GMRT and Effelsberg observatory, we estimated the flux density to reconstruct pulsar spectra. We find objects that have a maximum flux in their spectrum above 1 GHz and whose spectral indices are positive at lower frequencies. Some pulsars with a turn-over in their spectrum at high frequencies are found to exist in very interesting environments. We call these objects gigahertz-peaked spectra pulsars. 
J. Kijak, W. Lewandowski, O. Maron, Y. Gupta, A. Jessner
astro-ph.GA