Object Oberon
Oberon plus classes 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].