Lauther's Complete Punctuation Thesaurus of the English Language

This is the most complete guide to punctuation that I know. It is generally very useful. However, at times it tends to sit on the fence rather than to take a position. An example is the use of a comma when an interrupting phrase immediately follows a conjunction (section 21.12). The book gives four possible ways of handling this, but offers no guidance on which is the preferred or most usual option, or what principles should be applied in order to select the one most suitable to a given set of conditions.