R.R, N. and V.A., T. 2015. Non-Orthogonal Amplitude-Frequency Analysis of the Smoothed Signals(NAFASS): Dynamics and the Fine Structure of the Sunspots. Journal of Applied Nonlinear Dynamics. 4, 1 (Mar. 2015), 67–80. DOI:https://doi.org/10.5890/JAND.2015.03.006.