Measuring volatility in the Nordic spot electricity market using Recurrence Quantification Analysis F. Strozzi, E. Gutiérrez, C. Noè, T. Rossi, M. Serati and J. M. ZaldívarEur. Phys. J. Special Topics, 164 (2008) 105-115DOI: https://doi.org/10.1140/epjst/e2008-00837-1