@article{10_4171_ifb_106,
     author = {F. E. Benth and Kenneth Hvistendahl Karlsen and K. Reikvam},
     title = {A semilinear {Black} and {Scholes} partial differential equation for valuing {American} options: approximate solutions and convergence},
     journal = {Interfaces and free boundaries},
     pages = {379--404},
     year = {2004},
     volume = {6},
     number = {4},
     doi = {10.4171/ifb/106},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ifb/106/}
}