Albin, Pierre and Richard Melrose. "Fredholm realizations of elliptic symbols on manifolds with boundary" Journal für die reine und angewandte Mathematik (Crelles Journal), 2009.627 (2009): 155-181. Retrieved 23 May. 2013, from doi:10.1515/CRELLE.2009.014

Albin, P. & Melrose, R. (2009). Fredholm realizations of elliptic symbols on manifolds with boundary. Journal für die reine und angewandte Mathematik (Crelles Journal), 2009(627), pp. 1-235. Retrieved 23 May. 2013, from doi:10.1515/CRELLE.2009.014

Albin, Pierre and Richard Melrose. 2009. Fredholm realizations of elliptic symbols on manifolds with boundary. Journal für die reine und angewandte Mathematik (Crelles Journal). 2009(627): 1-235. Retrieved 23 May. 2013, from doi:10.1515/CRELLE.2009.014