More sums of Hilbert frames
  In this paper we have some new results on sums of Hilbert space frames and Riesz bases. We also have a correction for some results in "S. Obeidat et al., Sums of Hilbert space frames, J. Math. Anal. Appl. 351 (2009) 579-585." 
A. Najati, M. R. Abdollahpour, E. Osgooei and M. M. Saem
math.FA