Oberon pluSclaSSeS and methodS by H. MoeSSenboeck & J. Templ, 1989. See Oberon-2. ["Object Oberon - An Object-Oriented ExtenSion of Oberon", H. MoeSSenboeck et al, ETH TR 109 (Apr 1990)]. ["Object Oberon - A ModeSt Object-Oriented Language", H. MoeSSenboeck & J. Templ, in Structured Programming 10(4), 1989].