Lin, J.-W. . “Early Warning from Seismic Ionospheric Anomaly of the 24 May 2014, Mw = 6.4 Aegean-Sea Earthquake: Two-Dimensional Principal Component Analysis (2DPCP)”. Geofisica Internacional, vol. 54, no. 2, Apr. 2015, pp. 191-8, doi:10.1016/j.gi.2015.04.015.