hal-00678437 title_s Monotonicity of Prices in Heston Model auteur Sidi Mohamed Ould Aly journal International Journal of Theoretical and Applied Finance volume 16 numero 3 pages 1350016 doi 10.1142/S0219024913500167 fichier_hal https://hal.archives-ouvertes.fr/hal-00678437/document annee 2013 Identifiant HAL 621691