@inbook {2001, title = {S^2 type parametric surfaces with prescribed mean curvature and minimal energy}, booktitle = {Nonlinear equations : methods, models and applications (Bergamo, 2001) / Daniela Lupo, Carlo D. Pagani, Bernhard Ruf, editors. - Basel : Birkh{\"a}user, 2003. - (Progress in nonlinear differential equations and their applications; 54). - p. 61-77}, number = {SISSA;34/2002/M}, year = {2001}, publisher = {Birkhauser}, organization = {Birkhauser}, url = {http://hdl.handle.net/1963/1605}, author = {Paolo Caldiroli and Roberta Musina} }