Aphorisms 70-75c - Text of sections 70-75 with commentary by Lois Shawver. These sections concern definitions and determinacy of sense, and `family-resemblance' concepts. - http://users.rcn.com/rathbone/lw70-75c.htm
Obeying a Rule On Only One Occasion in PI §199 - Short article by James Still, approaches this section with a close analysis of Wittgenstein's dictum `meaning is use'. - http://www.infidels.org/library/modern/james_still/w_rule.html
An Introduction to Reading Wittgenstein - Article by Louis Shawver, covering just the first three sections. - http://www.california.com/~rathbone/wittgen.htm
The Grammatical Fiction of PI §307 - Short article by James Still, discussing Wittgenstein's approach to Cartesian introspection in section 307 of the Investigations. - http://www.infidels.org/library/modern/james_still/w_fiction.html
Can We Know Rules? - Article in two parts by Alec McHoul. McHoul is critical of the reception of rule-governed activity in the human sciences, and argues that attention to Wittgenstein raises doubts that rules can properly be considered the object of knowledge. - http://wwwmcc.murdoch.edu.au/aiem/wocat1.html