Maximum principles for minimal surfaces in ?3 having noncompact boundary and a uniqueness theorem for the helicoidhaving noncompact boundary and a uniqueness theorem for the helicoid
1. Instituto de Matemática, Universidade Federal do R. G. do Sul, Av. Bento Gon?alves 9500, 91509-900, Porto Algegre, RS, Brazil 2. Mathematisches Institut, Universit?t Heidelberg, In Neuenheimer Feld 288, D-69120, Heidelberg, Germany