1. Andreasen, J., Huge, B.N.: Expanded forward volatility. RISK 1, 101–107 (2013)
2. Antonov, A., Spector, M.: Advanced analytics for the SABR model, SSRN (2012)
3. Antonov, A., Spector, M.: SABR spreads its wings. RISK (2013)
4. Antonov, A., Konikov, M., Spector, M.: Free boundary SABR. RISK (2015)
5. Benaim, S., Dodgson, M., Kainth, D.: An arbitrage free method for smile extrapolation. Preprint (2010). http://www.quarchhome.org/RiskTailsPaper_v5.pdf