Grossinho, Maria do Rosário ; Faghan, Yaser Kord ; Ševčovič, Daniel Grossinho, Maria do Rosário, Yaser Kord Faghan and Daniel Ševčovič. (2017). "Pricing perpetual put options by the black–scholes equation with a nonlinear volatility function" . Asia-Pacific Financial Markets. Vol. 24: pp. 291-308. (Search PDF in 2023)..
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2017