J. Cañellas, A. Espinoso, J.F. Ortega, U. Melia, C. González, E.W. Jensen "Analysis of qCON and qNOX Anesthesia Indices and EEG Spectral Energy during Natural Sleep Stages", Advances in Science, Technology and Engineering Systems Journal, vol. 6, no. 1, pp. 1328-1333 (2021).