Oakwood Guidelines - A companion to the O2 language report which clarifies issues for compiler writers and users. - http://smalllinux.sourceforge.net/oberon/oakwood.htm
Object-Oriented Programming in Oberon-2 - Tutorial with history, descriptions, code samples, references. - http://statlab.uni-heidelberg.de/projects/oberon/kurs/www/Oberon2.OOP.html
The Oberon Programming Language: Hello World! - The Oberon Programming Language - information at University of Michigan. - http://www.engin.umd.umich.edu/CIS/course.des/cis400/oberon/oberon.html
ETH Oberon Module Definitions - Browse the auto-generated module definitions for the Oberon System 3 Versions. - http://www.oberon.ethz.ch/ethoberon/defs/
The ModulaTor Technical Publication - 72 issues of The ModulaTor: Articles about the programming languages Oberon-2 and Modula-2: programming examples, implementation notes, language comparisons, and language design. - http://www.modulaware.com/mdltr_.htm