The Economist
The Economist: Economist Style Guide: Punctuation
This resource provides a brief discussion of each of the following types of punctuation: apostrophes, brackets, colons, commas, dashes, full-stops, inverted commas, question marks, and semi-colons. Examples are included for each type of...
Other
Kim's Korner: Punctuation Rules: Question Mark
A single rule is given for question mark usage in sentences along with an example.